Tried several times on both XP(sp3) and Win 7 (sp1). No crashes, results the same on both...
Zipfiles contain...
Single files
1 -- 1 -- 0
Multiple files; single directory
1 -- 1 -- 0
Multiple files; multiple directories
1 -- 1 -- 0
Tried also with a mix of zips in a while loop, same result.