GPS Reception Problems with 396

Is anyone else having major GPS satellite reception problems with their
396? I've made two trips since getting the 396 and have noticed the
following...

After takeoff or on arrival within 5 miles of airports here in the
Phoenix Metro area I have _always_ experienced a loss of GPS signal.
This could happen even on a smooth, straight in approach (it's not that
I'm turning away from the satellites, etc.)

Outside the area, I've landed at other airports with no problems on
approach, etc. In cruise, everything is fine. Not sure what the issue
could be, but it is frustrating after paying so much for the product.
My GPSMAP 195 has NEVER lost sat lock as long as I've owned it.

This occured in two different aircraft (a Comanche, and an Arrow) one
of them even had a GNS 430 w/ a GTX 327, so I'm not thinking that it's
some kind of interferance issue.

Of course, I am using the external antenna, have upgraded to firmware
3.40, and have even done the almanac reset that was suggested by
support. No dice.

Anyone else with similar woes?

--Dan