I've encountered a major problem on Vista x64 SP1. When XnView is launched by an external program (e.g. Windows Explorer), the whole system freezes. Ctrl+Alt+Del doesn't do anything and the mouse doesn't move. The only way out is to press the Reset button. The problem to this problem is that it's not reproductible; sometimes I'll open a few images just fine, then one more and it locks up.
I can't even begin to explain how long I've searched for an ACDSee replacement (it's gotten lousy over the years and the old version has too many drawbacks) before I found XnView. I loved on Windows XP. What the heck am I supposed to do now, when I can't even help the author identify the problem?

Bright ideas welcome.