WP12 on Win98SE, filename problem?

I uninstalled WordPerfect 7, installed WP12, on my Win98SE system. Mostly it works fine. But there's one glitch which I can't figure out.

Working from w/in WP12 and navigating to some file somewhere, there's apparently no problem opening the file, regardless of the size of the filename and the number of words within that name.

But if I'm outside of the program and at the Desktop, and try to click to open a .wpd file with a "two-word or more" filename, the program returns an error msg and trys to open a file, one at a time, based on each single word within that multiple-word filename. The error msg reflects the results of an action to open a single-word filename - something like "can't open such-and-such a filename". Then it goes on to open the program in a fresh, blank, document.

I don't have trouble opening "outside" files with other programs, just WP12. I'm not convinced it's a Windows problem.

I'm thinking there some tweak in the program, but I've tried looking for such "configuration" rememdies. It might be in the Registry, but I don't know perzackly where to find it. And I've checked for the .wpd extension in WP, click Tools | Settings - Files, and the .wpd extension is there.

Any suggestions?
Thanks.