I have mature blocks, but I get "WARNING: Checkpoint too old" when I open the wallet.

Last block was 30 mins ago, network weight is 150,000 or so.

Edit:
Status: 1/unconfirmed, broadcast through 7 nodes
Date: 2016-01-11 19:17
Source: Generated
Debit: 0.00 PHS
Net amount: -343.627328 PHS

Still on the right chain?

> getblockhash 484037
> 036ce4101747222e37234e368edc9126f1a0b2b13a0448020dd52b6c400eeebe
> getblockhash 484040
> bbddc08a1fa08a03edce15a7e507800da645fbec3ceba18b3e40dd8aad99f7d1