I'm currently forced to use Win98SE *sigh*, because i use some programs not available on XP/2000.

As i had no opportunity to test OllyDbg on Win 2000, i'd like to know whether this odd behaviour also occurs on your machines:
When searching a process' memory, the computer freezes, depending on the size of the currently examined memory block. This means, you can't move the mouse nor do anything else, unless the memory block has been entirely read.

Does that happen on Windows 2000 and XP too?

That's not a OllyDbg specific problem. It's something to do with ReadProcessMemory(), it happened in my own debugging helper programs as well.