Catalytic Converter Popped Out of Its Flange!

[dag_dabreemie]

I've got a 1999 Audi A4 1.8T Quattro and about a month ago the Catalytic Converter popped out or broke loose from the flange.
Is this a common defect?
Here is a link to a youtube video someone else posted describing the exact situation:
YouTube - 1.8t cat converter disconnected
I was told it would cost about $1000 w/ labor to repair or replace. So I've decided to try and take out the CC and tack weld the flange back on it. The problem is that it has been a real pain taking and removing the cc out! I have my Audi up just on ramps. The 3 nuts 'n bolts on the bottom end of the cc are really hard to get at and I've drummeled cut one off already. I can almost pull the cc out and up through the hood area since I took out and removed the stock air box (gonna put in a HKS Reloaded short ram intake anyways) for more room. I've unscrewed the front sensor on the cc and detached the bottom sensor on the cc from the connector module. The cc + mid "down pipe?" would be able to come out if it weren't for the bracket brace that is attached and welded to the mid "down pipe?" that gets caught and is unmaneuverable up through.
What is the best way to remove the Catalytic Converter and reinstall it? Any help is appreciated.

[Mawhitey]

Sadly it is common, its to do with different metals contracting at different rates etc. It can be welded back on no worries, as for the bolts, i think you need pb blaster or similar to free the bolts up, spary lots on and let it soak