thank you for your insights. i knew something was amiss in my perfect world of stellar navigation. i mean, i hit where i'm aiming, but it's not really the laser-like precision we'd hope for.
so, being a white guy, and the sort that blames the keyboard for bad spelled words, i predictably replaced the gps unit. and that was better ... but not the embodiment of technical perfection (and Spelling ! ) for which bpl members strive.
so, it's all good now. and Thank You. you've given me the information i need to do a better job.
on replacing the old GPS :
it's not all compass correction numbers. there is an article in wikepedia titled "Failure modes of electronics" and, as i work daily with electrical/electronic equipment that arrives to my bench already broken, it rang very sound and true. i was already knocking on the door of not expecting equipment/tools/gear/systems to last indefinitely, and budgeting/purchasing accordingly, as well and including the theory in my sales presentations. (let's don't load the customer up with equipment he's not going to profit from in a timely manner)
this led to thinking that a well proven, but vintage gps, vs the very minimal cost of a new one, is probably a sound investment if one is serious about having it working. this, even though the old unit showed no documentable signs of disfunction.
all that said. the older geko has a better interface and is a Vastly more appropriate color vs the foretrex 401.
thank you all,