The daemon auto saves, when this happens if it takes to long to save the blockchain the wallet will time out. Obviously on the pool this is not good as then different modules will freeze up.
I understand this may be an issue for pools and exchanges.
Proposed fix will make wallet try later, which may be a good idea but more suitable fix is in testing atm.
You can however edit the code and build a custom wallet with this fix.
Problem will be addressed in next release, which may take some time.