this can be caused by IE.
Can you tell us what OS these are failing on as well as whether it is x64, x86, or x86 for x64.
What you can do is enable the terminate process for IE in the packageboot script.
It is disabled by default.
Somehow when Java is being installed, IE is being invoked and it is locking a file.
This is what causes zipper to fail.
We are closed today, however please send this information to www.solarwinds.com/customerportal and we will get you fixed up tomorrow.