Re: repair pst
A third party repair tool, like the one advertized above, might be the solution in certain cases and certainly worth a try if other methods fail. It's essential that it has a free demo mode, so you only pay for its use if that shows it will be effective.
But with a pst-file containing important information, it's essential that it's included in any users regular backup scheme. Then, if info is missing due to some corruption, it can easily be retrieved from the uncorrupted backup. That's better then trying a recovery of a corrupted backup.