Orthoflex Cutback: Saddle Slipping

["guest@endurance.net" <guest@endurance.net>]

Nina Bomar caballos@att.net
I purchased a new Ortho Flex Cutback about eight months 
ago.  After trying several pads, I had a pair of Skito 
Booties with wool backing and the foam inserts custom made.  I have washed the pad several times, but it seems the saddle slips from side to side (just a little bit, but enough to be annoying).  My horse never has a sore back and we have completed a few 50's with this set up.  I ride with the cinch snug so I don't know what the problem is.  Should I try synthetic backed booties?  Do O.F. saddles need adjustments after a period of time?  Any suggestions?