Assertion Failure - Ubuntu Lucid

I’m running Ubuntu Lucid (32 bit), all packages up to date. I had run bitcoin 0.2 previously, and just downloaded 0.3. I ran bitcoind and I got:

bitcoin: main.cpp:823: unsigned int GetNextWorkRequired(const CBlockIndex*): Assertion `pindexFirst’ failed. Aborted

So I ran the bitcoin GUI, and it came up and showed my existing coins, but quickly gave me the same error and died. Then I went back and ran the 0.2 GUI again and I get:

bitcoin: main.cpp:743: unsigned int GetNextWorkRequired(const CBlockIndex*): Assertion `pindexFirst’ failed. Aborted

Has my db got corrupted? Do I have a broken dependancy?

I tried to build 0.3 from source but got many errors, probably missing some *-dev packages. Will look at that more later.