After upgrading my RAM from 1 GB to 3 GB the bitcoin-qt client didn't work. While loading the blockindex a fatal error occured. It said:
Db::open: Invalid argument
C:\Program Files\Bticoin\bitcoin-qt.exe in Runaway exception
I'm running a 32-bit installation of Windows 7 on an Acer Aspire M3640. I have made a backup of my wallet and reinstalled the bitcoin client. Now it says:
CDB() : can't open database file blkindex.dat, error 22
C:\Program Files\Bitcoin\bitcoin-qt.exe in a Runaway exception
I deleted the blockindex (blkindex.dat, blk0001.dat, blk0002.dat) and the known peers (peers.dat, peers.dat.a2de, peers.dat.da53, peers.dat.f4a4). Now it works fine again, but of course I need to redownload all blocks in the network.
I'm not sure whether this is a known issue, I'm sorry if it is. Thanks in advance.
Are you sure that your RAM isn't faulty? you could test it with the windows 7 built in memory tester, takes hours to test I think.
Closing this issue as it was solved by redownloading the block database. Work is in progress on automatically detecting a corrupt database and rebuilding the index / redownloading when needed.