Yup, I did. As I said, the problem occurs as soon as I install MsgPlus.
Well, there is some report.
AppName: msnmsgr.exe AppVer: 8.1.178.0 AppStamp:45b12d6a
ModName: riched20.dll ModVer: 5.40.11.2218 ModStamp:41941afb
fDebug: 0 Offset: 00001704
I think the problem might be with riched20.dll. I will try a different version...