Delete, rename, or move out addr.dat. If the problem persists, then examine db.log again (latest messages). If it complains about any file which name starts with "blk", delete and re-download the block chain.
All the essential data are in wallet.dat.Another file that you may want to keep is
bitcoin.conf.
Block chain is stored in
blkXXXX.dat and
blkindex.dat. Replace them with files from the latest
http://eu1.bitcoincharts.com/blockchain/blockchain-XXXX-
XX-
XX.tar
"database" contains transaction logs for block chain and peer databases.
I think, it should be deleted when replacing block chain files.
addr.dat contains peer addresses. You may have to delete it if transaction logs are deleted or damaged.
__db.XXX – some database files. You may have to delete them as well.
.lock – can be deleted.
*.log – can be deleted.