Routers, Frame Relay and IPX

[polaris]

I have constant problems with IPX sap tables in my Bay Routers. Periodic updates are on but at 1 hour intervals. The sap list is in the range of 4000 entries. Tables are routinely corrupted. My BCNs have T1 frames and the remotes are generally 56K. Hub and spoke topology. Two pvcs per site. One primary and one a backup(to another router). Both 56K cir. 1000s of NT workstations have been installed in our network with the sap agent enabled. I have been filtering these 0640 sap broadcasts at the sources. Question, If I turn periodic updates off, will NT machines going on and off still force router rip and sap updates (entire table)? I am concerned that the frame relay network is eating the sap updates up. I don't currently have trafic shaping enabled at my BCN because Bay has so far failed to tell me if buffering at the port, to match the remote CIR, will hog the memory on my slots(octal sync 64K) and drop packets. If I don't keep periodic updates on, then sites will never come clear unless I intervene.