From what we can tell there's a uncommon condition on the network (seems to be about 1 in 10 clients), where some databases have became corrupt. Please check your logs for these messages:
--
2015-02-15 17:34:26 ERROR: ReadBlockFromDisk : Deserialize or I/O error - ReadCompactSize() : size too large
OR
2015-02-15 17:34:26 ERROR: ReadBlockFromDisk : Errors in block header
---
If you find entries like that delete ~/.darkcoin/blocks and chainstate, then resync from the bootstrap:
https://github.com/UdjinM6/darkcoin-bootstrap
Thanks 
All my masternodes actually had these in their logs. Have since resynced from bootstrap.
I'll be firing up my masternodes tonight now I'm back home. Will probably delete and resync them all too just to be on the safe side.