Quote from: Matt Corallo on May 05, 2013, 03:58:58 PM

Ahh, this is your problem...yes, raring had no packages whatsoever in the PPA, so when you installed bitcoin-qt, you actually installed Ubuntu's version, which depends on libdb5.1, making your wallet incompatible with bitcoin.org's binary releases. Raring currently has the latest 0.8.1, however Ubuntu is not likely to keep that up to date as new releases come out. If you have a backup of your wallet prior to the upgrade (I'd hope so) and you haven't done anything with it since, you can just restore that backup and use the PPA versions. Otherwise you will have to either continue using Ubuntu's version (remove the ppa, remove bitcoin packages, reinstall, and hope you dont fall too far out of date) or build your own bitcoin-qt/d and keep doing so using libdb5.1.

Ah, mystery explained -- thanks!

I've removed the PPA and "downgraded" to Ubuntu's version, and it works fine now. One problem remains, however: sooner or later I may need to upgrade to the PPA version. When that happens, I'll need to convert the DBs.

Am I correct in assuming that the blockhain DB is using LevelDB and does not depend on libdb? And is therefore wallet.dat the only critical file still using libdb? If so, I can easily migrate simply by exporting+importing the relevant addresses. Or is there something I'm missing?