midi bank triggers samples on different bank

not sure what Os im on/pretty sure its old.
i have samples on bank A but not on bank B.
Bank B has only midi notes assigned. When i assign a midi channel to a track and play the pads all seems normal (playing synth from mpc pads). when i play the sequence/track back the samples on bank A are being played by my bank B pads.
ive checked for a second sample layer/there isnt one assigned.
this behavior did seem to come after i left the mpc pn fpr a day or two. ive turned it off and reset the machine but the problem persists.
I noticed last night that this is only happening with the bottom half of the pads./ not the top two rows.
any one run in to this?
meech-
if this message is irrelevant to this section because i'm not sure about my OS i will delete it. just lookin for some feedback while i trouble shoot

Its not irrelevent. Why wont you just get the new OS. Save your program, update then see if it works.

Thank you ! i will update the OS tonight and follow your advice. that dirty sanchez animated GIF is off the chain btw.
thanx
meech-

Pretty sure it was just the (Program assign) setting on the track that i was neglecting to notice.
Setting it to a program with no samples solved my problem.