Songbird crashes on startup - database specific

I've been weening myself off itunes, and it's sadly not going too well. I have a bunch (over 30) of smart playlists, which was time consuming to set up. The first time I did so, songbird froze while exporting to iTunes, so I had to kill it. My database got corrupted, and songbird wouldn't boot.

I started over, disabling itunes export. Finally got all my playlists created last night, and today when I load up songbird it won't start again! Each time I get the "crash report" dialog.

I've moved the files out of ~/Library/Application Support/Sonbird2/******/db/ and it boots fine. I put them back, and remove all the files from the extensions/ folder, and it still won't load. Which makes me fairly confident that it must be a database issue.

It's worth noting that I quit and relaunched songbird a number of times last night during and after making all my playlists, because I'm developing an extension. There were no problems then, so it can't be completely deterministic.

my main library file (main@library.songbirdnest.com.db) is close to 30mb

Here's a couple crash report links:
normal: http://crashreports.songbirdnest.com/...
all extensions removed: http://crashreports.songbirdnest.com/...

I'm a developer, so I'm happy to run custom builds, use a debugger, etc. I really want this to work, if someone can tell me how.