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This might be one, suboptimal, answer for you. Check out the following question:

The user fixed it by recreating the package in question and copying appropriate files across. They never tracked down the real cause of the problem.

Actually if this answer works for you (don't forget to make the backups!) then you'd probably be doing the community a service if you explored what the problematic difference is between the failing package and the recreated one (by using a backup of the problematic package and reintroducing its differences one by one). Things to pay particular attention to are file permissions, hidden and configuration files, different file contents.