I had the same problem, but resolved it by deleting the ~/Library/Application Support/TextMate/Support directory (without trashing any installed bundles or the application itself, Rev 1349)

Blogging worked with no modifications, so I would toss your TM, toss your Application Support/TextMate folders in both ~/Library and / Library (or save to desktop) and try again.

Also make sure you Check For Updates in Prefs and get the cutting edge version