If you have been working with LR3 Beta and have a current job on it ...
While the upgrade to LR3 did transfer my LR2 Catalogs with all corrections intact ... it did NOT transfer the one I currently have (or had) on LR3 Beta ...
PLUS, LR3 Beta closes out and expires when you upgrade, so you cannot revert to LR 3 Beta to retrieve previous corrections or finish the job.
It may be an anomaly, or I may have done something wrong somewhere, but the LR3 Beta back-up catalog is gone. No search works, and when I finally found the back-up catalog with the right date, there were no photos in it.
Oddly, all of the Photoshop tiff corrections from this job were intact (edit-tiffs) in the original RAW folder ... but none of the LR adjustments were there ... nor any of the Quick Collection filters.
If there was a warning about this, I missed it.
I'd recommend finishing any job on LR 3 Beta and saving it out prior to upgrading ... or make darned sure there is an intact back-up off line.
P.s., if there is some insight I missed please do share it