On my second machine that was stuck at 608 I did the following:
- made sure I have the latest wallet running: v0.8.54.0-unk-beta
- closed the wallet
- deleted folder ./memorycoin (!!! but beware not to delete your wallet if you got some MMCs!!! If so make a backup before!!! )
- restarted the wallet
- did "addnode 180.183.155.90 add" and "addnode 103.11.49.151 add"
- waited until blockchain was downloaded from scratch
all synced now

Thanks - you might get away with just deleting peers.dat - this will force your client to re-evaluate the nodes on the network.