535,710 is what the explorer says... both of my clients stopped syncing earlier today. I have tried many restarts and re-syncs. I cant get but block number 1 to sync.....

It appears that the v1 chain was attacked earlier this morning. MrData has published new source which adds checkpoints to resolve the issue. Binaries are not yet available for this fix.
More to come...
New Win32 binaries have been distributed to resolve this issue. Unfortunately, the block chain may need to be deleted and re-downloaded to solve the freeze-up... Try the binary first, if that fails to sync then clear your block chain and re-download.
I apologize for the inconvenience this has caused anyone. Please let me know if a new v1 Mac is needed, or not. Is anyone still using a Mac QT for v1?
Follow the download links on the OP or
http://www.was.club/.