1 - The unit may need to be reflashed and that's only done at a
service center.

bummer -- I can expect to be w/o it for how many months? ;-)

2 - The most likely cause based on your symptoms is a cracked crystal
in the transducer. Replace the transducer first and see if the
problem goes away.

****er. how do they get cracked? I've not struck anything nor has it been
dropped prior to install (at least while it was in my hands)

3 - Don't take any crap from Garmin. Their customer service, in my
experience, is lousy.

They used to have good service, way back when....

Thanks
-josh