... may not be correct! You may need to upgrade, or other nodes may need to upgrade."
I used the Debian namecoin-qt binary from
http://namecoin.info/ and it worked fine except that sometimes the blockchain is messed up.
This morning I got the message from above so I downloaded the current source from
https://github.com/namecoin-qt/namecoin-qt and built it as described in
http://dot-bit.org/BuildNamecoinQTFromSource.
However, the message stays the same and the blockchain is not updated.
What is wrong?