Gentlemen, we are testing 3.320 right now.
The problem with files disappearing, we think, is directly linked to our trying to be 100% Microsoft compliant for Vista. This requires removing all KMA and working files (Songs database, playlists, etc.) from where we have been installing them for 7 years, which Vista WON'T allow.
With 3.320, we now detect if the Windows is XP/2000 or Vista when you select Upgrade (versus Replace). If XP/2000 we don't move anything as it is not required. If Vista, we must move it and now show an HTML page with instructions to print and follow. We have been HIGHLY CRITICIZED by some of our own Beta Testers for requiring our users to disable the UAC (User Access Control) in Vista's security. However, we now have PROVEN that Vista will NOT allow us to move KMA files from where you have been importing them, if you used our default folder. We MUST move them, so disabling the UAC is the only way.
If installing Hoster by Remove, or for the first time, all Windows versions are installed the same; Vista compliant. Since this is a new install and no KMA and other working files exist, there is no problem with files "disappearing".
We are hoping to get a buyoff on 3.320 from our Beta Testers tonight/tomorrow so we are confident to release. In 30 years in business, MTU's products have NEVER lost user created files. This has been a nightmare for us! However, we now believe our latest round of changes should fix the files problem.
Ddouglass is one of our very best, technical helpers; a true asset to MTU. However, it is my understanding that whether you remove any program with Windows Add/Remove Programs, or run our Installation program and select "Remove", they BOTH run the same "uninstall" program created by our Installation program when Hoster was installed. What is placed on the hard drive, or created during installation, is "known" to the Uninstall program. What is created by the RUN TIME program (Hoster in this case), is NOT known to the uninstall program and thus cannot be removed by running it. Thus, KMA, Songs Database, Playlists, log files, etc. cannot be removed by Uninstalling.
As to importing singer's disc tracks, I am sorry to admit, we have not addressed that problem yet. Sometimes "vaporous" things happen that are not easy to explain or track down. This is one of those. It may disappear in 3.320. If not, we'll try to find out what changed from 3.312 that could cause it. I don't question at all that something has changed. The problem is getting the time to dig this out. It is NOT easy, and could take weeks of time to solve; weeks we don't have available at this time. Thus, for those having the import Singers disc slowdown, the only answer right now is to install 3.312 or maybe as high as 3.316 for now.
We are in the midst of developing Hoster 4.000, at Beta 14 released today for testing with Tempo change for the first time. To provide all the features requested by our users over the past years requires several major "core architecture" upgrades. They are very risky and time consuming, but we are now doing these with extreme testing. For example, the Player code had to be totally rewritten from ground up. The new code allows Tempo change, key change and crossfading with 2 songs playing at the same time. It also allows selecting the audio ports to play out, and adding a second Preview Player (audio only) in the Search dialog so you can hear a song before adding it to the Playlist... while anything that can happen is going on in the Play screen.
We are doing our best to balance our programmer resources between upgrading 3.3xx to handle incredible Microsoft bugs in Vista, and advancing 4.000. We are WAY behind when I hoped to release 4.000 because of all the problems Vista has caused.
Also, a decision I sorely regret having made... we believe we now have perfected importing and playing ZIP files. Many of our new users have had incredibly difficult problems to diagnose with ZIP files they did not create, but rather got over the Internet or on eBay...
illegally! They are the bums who are driving the income down for honest, disc-buying Hosts.
I truly regret ever supporting ZIP files! 
The ZIPs they have are created with all manner of problems we have never in 30 years seen before, including MAX zip compression that not even WMP or WinZIP will handle. Hoster now handles EVERYTHING our users have run into. However, we have paid dearly to obtain this, and it has created problems along the way. For example, when we deleted the Windows \Temp folder to free up the unzipped filenames so we could re-use the same name, depending on how your Windows was used recently, it could delete Desktop icons and even some recent files (such as our Songbook.rtf file)! Why does Windows do that? With all the security they enforce on us, how could they leave things in the \Temp folder that should be protected? Go figure! But we had to learn that one the hard way.
KMA files seeming to disappear are in this same category. After months of research and testing, we did what we felt was the safest and easiest way to move the KMAs. It proved to be a disaster, and we have been focused 1000% on a solution. On top of that, some users' hard drives have had separate problems not related to Hoster. Try working with each user to discern what is what... that's stolen even more of our time to solve each problem.
I understand your feelings and wish I had a magic wand I could wave. As President of MTU, all I can do is focus our team to tackle each problem one at a time until each is finally solved. We are making progress as fast as we can, with new releases coming out weeks apart to get fixes to you as fast as we can. Then, you find more problems, and we go back and spend weeks solving them. We're just as frustrated as you.
Your income is at stake, and our reputation is at stake. After 31 continuous years in business as MTU, I'm not throwing in the towel. We're still fixing the problems... one at a time.
As I go to bed tonight, for the first time in many months, I truly believe we finally have solved all the file problems in 3.320. We'll see when we release. 