nyria: could you please try the attached dll (just replace the one in your Mediaportal installation directory). it is essentially the same as the one from the installer, but contains a bit more debugging output about the activity surrounding the things that happened in your original logfile. after a crash, please attach evr.log, which should be in c:\programdata\team mediaportal\mediaportal\log. (the topmost directory may be hidden).
Sure i will give a try, i'll post a log when mp crashes again.