catastrophe recovery outlook–pls help!

Microsoft lost all my mail in my upgrade to Office 2003. The pst file is totally not there,
a search was done of the whole hard drive.

I called Microsoft, and they said that it loses that file only 5% of the time. “Oh well” was basically all the support person said.

Does anyone know if there is any way to recover this mail? Seems like I heard somewhere that if the file is a certain size, that it will rename it to something else.

Thx