I'm wondering if there's any pattern to the assignment of extensions for PocketWord files on my pocket pc?

Sometimes they have a straight .rtf file extension when I look at them in Windows explorer (e.g., if I take my sd card out and look at files on my desktop), and sometimes they are given a .psw extension. Sometimes they have a .doc extension. If they are .doc or .rtf extensions, I can open them on my desktop, but the .psw does not, even though it opens seemlessly on my ppc.

Any help here would be greatly appreciated.

Thanks in advance,
TB