Michal,
We are seeing this occuring in very limited situations (maybe 5-10 installations?), but we have not figured it out. There is a problem during the "loading" of the program in a system DLL, NT.DLL - our software has not even officially "started running" yet. Our research shows other applications running on some installations of XP SP2 having similar problems.
Some theories out there on the various bboards think its some Vista code that is in IE7, in combination with XP SP2. One developer who worked on IE7 says that it cannot be, because the Vista version of IE7 that is installed is different binary from the one on SP2. Other's have said it is due to having a Beta version of IE7 and then installing the release version of IE7, there is still some "buggy beta" code out there.

However, NONE of this helps you. We have been able to duplicate the problem in house on one of our "new" computers, but the crash occurs in a system DLL during the load, and there is nothing on the "call stack" of our code (it's all o/s code from NT.DLL).
Try running Windows Update for your O/S and for IE7??? If that doesn't work, possibly try uninstalling IE7, putting on IE6. If DSP works, you may then try installing another browser or even IE7 again???