I'm using version 1.5.9 - just moved onto Vista and could not install the Sony software at all BUT MPE works great!!
There is one little problem - the icon for 'Minimise to tray' does not always appear in the correct place. Sometimes this can be fixed by minimising and restoring MPE.
Also if you 'click and drag' MPE window then the 'Minimise to tray' icon always appears - but not exactly in the right place - but the functionality does work as before under Windows XP.
Great software - really - if you are able to fix this small detail that would be great!
Many thanks