[ddouglass]

Laptop or Desktop type of computer.
Does it do this from the first song on or is it something that shows up later in your show.
There are a few things that come to mind.
Clean out the temp files in Internet Explorer, in your profile (C:\Documents and Settings\(login name)\Local Settings\Temp), and in C:\Windows\Temp.
Defrag your drives. Especially your C: drive but if you have your songs on another drive defrag it too.
Check the "Free" space percentage of your C: drive when you defrag (the program will tell you. If it is less than 25% then you need to move or delete something. Windows needs to have a minimum of 20 -25% free space in order to operate efficiently.
The next thing is physical, so if you are uncomfortable doing it then take it to a professional (preferably not Best Buy) and have the computer cleaned to get all the dust and dirt out. This causes the computer to overheat and not run as well as it can. Many laptops will actually shutdown some memory (use less) to help keep the heat down so the processor won't overheat.
Then by all means upgrade to 4.08. I and MTU realized that there were problems for some with 4.05 and even 4.06, but all of those problems have been solved. Don't do this until after you get this problem solved though.