I'm using:
Devcoin version v0.8.5.1-g25a7d46-beta
The latest one on the site. I got almost fully synched last night and then it got invalid blocks again and won't start,

.
Try to remove block chain, leave only wallet.dat and devcoin.conf (make a backup of wallet.dat, if it has the money)
In devcoin.conf write:
rpcuser=devcoinrpclogin
rpcpassword=devcoinrpcpassword
listen=1
daemon=1
server=1
gen=0
rpcallowip=127.0.0.1
rpcport=52332
irc=0
connect=199.192.77.162:52333
connect=82.200.205.30:52333
connect=69.197.61.58:52333
Do not write "addnode", write "connect".
"connect =" - connection is possible only to a specified node.
"addnode =" - a node that connects to your wallet sends the entire list of nodes. Among them may be nodes with incorrect block chain
After synchronization can be rewritten to "addnode".
Sorry, my English is very far from perfect.Will try with your settings. And I've been deleting everything but wallet.dat. It always locks up on one specific block and throws error after error: 167999
.