Did you set the desiredCompressionMethod to COMPRESSION_DEFLATED?
If that doesn't help, (short) working code that exhibits the problem may shed some light. Alternatively, you could try using an external command-line driven zip program instead of Archive::Zip.
update: I did some experimenting, and I've got nothing. I note that jar can be very picky about its input format, and that although I've used Info-ZIP on linux to create/modify some working jars, I've also run into problems with it (anecdotal - I's been a few years since I tried any of that). Conservative advice would be to unpack the jar however you like it, modify whatever you need, and use the jar program to create a new jar, since that at least should work.
In reply to Re: Archive::Zip Problem: Zip versus Jar file formats
by Joost
in thread Archive::Zip Problem: Zip versus Jar file formats
by sblanton
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