Had the same issue.

Traced it to a bad antenna. Garmin FedEx'ed me a new one. The problem
is demonstrated when in line of sight to cell phone towers on certain
frequencies. Test it out around town, and you'll see what I mean.

--Dan

Mike Spera wrote:
Its bbbbaaaaaaacccccckkkkkkk.

I thought we had the 396 reception problems solved with the unit swap
and upgraded firmware. On climb out the thing lost its lock again and
continued to do so until I changed course. That ain't gonna be an option
on a plan in IMC (uh, center, I need to change heading 30 degrees or so
to get my VFR GPS back on line...).

I tried switching freqs. on the nav and com radios to avoid harmonic
interference. No difference. I wonder why this cropped up after 3+
months of problem free reception??? Last time this was happening, I
tried running the unit on batteries, switching the GPS antenna around,
and a host of other things. Nothing helped until I upgraded the firmware
on a new unit. It has been solid since then with 6+ sats near the top.

Now, garbage again.

Anyone else see this problem on theirs?

Thanks,
Mike