bitcoinqt not resyncing

[DavidZ]

Hi my bitcoinqt wallet unfortunately is not resyncing any more. It is now 31 hours behind. I am getting a warning message which says "Warning: displayed transactions may not be correct! You may need to upgrade or other nodes may need to upgrade." I'm running v0.8.5-beta under debian linux wheezy/gnome. How can I get it to resync? At least I still can transfer out bitcoin.

Thanks,

David