Bitcoin will not start up after upgrade to 0.5.2

[GideonGono]

I downloaded bitcoin 0.5.2 yesterday replacing 0.5.0rc7 which I was using before. The blockchain updated as normal and I exited. Today, I tried opening bitcoin-qt from terminal and it showed the loading screen but it quickly disappeared and the following error was left in the terminal window:

Code:

ubuntu@ubuntu-desktop:~/$ bitcoin-qt


************************
EXCEPTION: 22DbRunRecoveryException       
DbEnv::open: DB_RUNRECOVERY: Fatal error, run database recovery       
bitcoin in Runaway exception       

terminate called after throwing an instance of 'DbRunRecoveryException'
  what():  DbEnv::open: DB_RUNRECOVERY: Fatal error, run database recovery
Aborted
ubuntu@ubuntu-desktop:~/$ 

Now bitcoin will not start and neither will the headless daemon. I have a backup of my wallet. How do I fix this?

BTW I use Ubuntu 10.04

[jake262144]

One of the databases⁽¹⁾ (either the block chain or the wallet) got corrupt.

Move the block chain data (addr.dat, blk0001.dat, blkindex.dat) into a temporary sub-directory so bitcoin-qt can't find them.
If any of those files were damaged, bitcoin-qt will now launch and start downloading the whole block chain from scratch.
If bitcoin-qt still fails, put the block chain files where they belong and deploy your backed-up wallet.

Notes:
(1) Actually, I should have said "At least one" but an event resulting in damage both to the block chain data and wallet is very unlikely.