orb85750: It would probably be best to take everything out, make sure all contacts are clean, etc.. I would double-check the 1260, try removing and inserting the card several times*, if you have a good, safe contact cleaner, use that. (I use Tun-O-Wash by Chemtronics, safe for PCB's and all plastics, probably not too safe for people, tho :-o ) IME, 1260's are quite dependable, but once or twice the contact between my 1260 and 1200T got dirty or somthing, and it showed the same symptoms you describe.
I know it's a pain to take everything out, and start over... But, really it's the best way to find out just what's wrong on your system. (I had to do that with my troublesome A4000T, still in pieces awaiting a better PSU .... :shrug: