- Is the client showing "syned to network" or is it still syncing?
- run a "history" in the console (in the advanced menu)
I have a similar problem - no balances, no transaction history, even though its showing Blocks are Synced, and I used the client with no problem just a few days ago.
I ran "history" in the console for my accounts, and they each come back with "No transactions found".
May be incidental, but I also noted that whenever I change my preferences for the "logout timeout", they are not being retained for the next time I log in.