I guess I'll reply to my own thread just to post what I've learned over the past few days in case it helps anyone else. A driver upgrade (actually the entire platform) on the MC9060's fixed their connectivity issues.
My Zebra QL420 printers remain a problem. At this point we are considering an upgrade to the QL420 plus.
Cisco confirmed the 1242's are using a different radio and chipset than the 1231's. All the suggestions made by Cisco to turn off G data rates, disable aironet extensions, had no real effect on getting the printers to work with the 1242's. We did retain the WPA handshake timeout setting of 500.
The zebra printers seem fairly cantankerous in the LWAP environment as well, but that is another thread.
