TSW Double Grover

[nth-wave@easynet.co.uk (Dave)]

Okay, I know that this subject has been discussed recently, but since it
didn't apply to me then I paid little attention to it ...but now....

I have recently bought the 12inch Sensual World single on record.  It's got
The Sensual World on the a-side and WSDTM and the instrumental on the
b-side.  On the a-side there is a double grove and it plays both the vocal
and the instrumental

My two out-of-date questions are:-
Is this a common feature of all TSW singles?
Is the instrumental on side a the same as side b?

Thanks people

Dave

BTW I saw one of the many bootlegs of the tour of life the other day and i
found it quite amusing that the CD cover had a picture of a woman i can
best describe as Cyndi Lauper.  Someone screwed up.