We have many customers who runs LSI with Cashcade, and everything is working normal. It could be the Firmware build with your current controller causing this issue, or there is an issue with one of the disk(s).

In case if the data get corrupted on the Primary box, if the replication service kept running then the mirror will get corrupted too. Having Snapshots, Backup in such cases should help ( in some cases ).

Also you may find the following Forum link and KB useful for you:

http://forum.open-e.com/showthread.p...achecade-2-Pro
http://kb.open-e.com/How-to-dramatic...ance_1293.html