Connection issues and pool not submitting work fast enough. 
Also hashrate feature doesn't work, but I'm sure you knew that already.
Also hashrate feature doesn't work, but I'm sure you knew that already.
Im busy looking at the problem right now, clearly running for a day without little to no problems was to much to expect ;P
re hashrate, ye something isnt calculating correctly it has to do with db import delays need to sort that out.