I also suffered inability to open Hoster (flag - reg info not matching serial no.) after upgrading to v3.08 but eventually after many uninstal/reinstal actions got programme to open.
I have just downloaded v3.10 and problem recurs Three times I have manged to open 3.10 and use it only for it to fail after one or two loadings.
I am unble to get it to load again even after transfering all previous download files to removeable disc and loading only v3.10
Ivor