Originally I made polib behave like MS lib, storing any specified path for each member file. After that I havn't given it much thought.
Looking at it now (quickly), this seems rather useless. I think the only time the path matters is when extracting a member from the archive: it helps separating thispath\name.obj from thatpath\name.obj - but this could be handle in some other way.
The IDE will always use fully qualified paths internally, and also pass them to external tools, so this is why they are included in the generated libraries.
It's a little late to do big changes for version 8.0, but I will look at this for a later version.
For now, what you can do is this:
1) Create an empty directory
2) run "polib -explode some.lib" in this directory
3) run "polib *.obj -out:some.lib" in this directory, assuming there are no duplicate (base-)names in the library
Not specifying a path for the "*.obj" part should remove all paths from the library...