Scanner problem: stimon.exe page fault

I bought Agfa Snapscan e20 (USB)scanner but I can’t use it because everytime I try to scan I get the following errormessage: “STIMON caused an invalid page fault in module STIMON.EXE at 017f:00407e9a”. Windows (98SE) shows the scanner in Device Manager and says there is nothing wrong.
I tried updating the drivers and even reinstalling Windows but nothing helped. I also tried to run stimon.exe manually (which is suggested on many pages about stimon.exe related problems) but it didn’t help either. If someone could even tell me what might be the source of the problem (deviceconflicts?) I would appreciate it. I know what stimon.exe is and what it does, no need to explain that part (that is usually the only answer one gets when asking about stimon.exe problems).