I've read that re-installing PocketMac can fix this issue. That's the only fix I've seen however. No idea what the error message means. Sounds like something got corrupted, which would be why a re-install would straighten it out.
There's a thread over at CrackBerry dealing with fixes for PocketMac:
Problems with PocketMac? Follow these steps first - BlackBerry Forums at CrackBerry.com