Crash upon startup

Hello,
I used to be able to run the wonderful MuseScore software until a month or so ago. When I tried again yesterday, the splash screen would come up and a little while after that I'd get the well-known Windows message about the programme being terminated, asking me whether I'd like to send some error report to Microsoft. Thus, MuseScore doesn't start any more.
I installed the latest MuseScore release 0.93 over my installation, no change. I uninstalled MuseScore completely and reinstalled 0.93, still the same.
Windows event log says:

Fehlgeschlagene Anwendung mscore.exe, Version 0.0.0.0, fehlgeschlagenes Modul qtcore4.dll, Version 4.4.2.0, Fehleradresse 0x00074a79.

Weitere Informationen über die Hilfe- und Supportdienste erhalten Sie unter http://go.microsoft.com/fwlink/events.asp.

(Faulting application mscore.exe, Version 0.0.0.0, faulting module qtcore4.dll, Version 4.4.2.0, fault address 0x00074a79.)

A Google query reveals that this seems to occur with several applications that use Qt, yet none of the forums I found provided a solution (I happened to find only some non-developer forums where the answers boiled down to something along the lines of "We'll try and fix it. (...) We fixed it. Update our software XYZ." without describing the steps necessary to fix the problem).

This problem occurs under Windows XP Home SP 3.
Is this a well-known problem with Qt, and is there any way to avoid it (besides only using MuseScore under Linux, which I'm doing at the moment)? There seems to be no similar report in these forums.

Thanks in advance.