re: motorbike entitlement had vanished
On occasions, it is sometimes of great benefit to "lose" your licence when getting renewals, as DVLA will not accept a photocopy as any form of proof whatsoever. My friend found this out to their cost and strangely enough, again, it was the motorbike bit that had been wiped.
The lesson here, is never to give up your licence until the new one has been issued correctly.
Perhaps one way of solving this, is to recommend everyone rings up the DVLA prior to sending the documents back, to enquire as to what the computer is showing. Once DVLA goes into meltdown they just might consider revising their obviously flawed processes.