"Could not continue scan with NOLOCK due to data movement"

This one is mostly caused by using NoLock hints or the read uncommitted isolation level. If you're getting it a lot, remove Nolock from your queries (probably a good idea anyway considering the incorrect results it allows). If you need writers to not block readers, consider one of the snapshot isolation levels.

See - http://blogs.msdn.com/b/davidlean/archive/2009/04/06/sql-server-nolock-hint-other-poor-ideas.aspx

The timeout suggests IO contention or other problems, if the RAID controller is resetting frequently, then you may want to investigate that, see why and if it can be fixed.