Seronac

My new Garmin eTrex Vista HCx is great, but it's off a bit: by about 100 ft. to the east. In other words, it thinks I am about 100 feet east of my actual position, as compared to a number of other sources, like Google Earth, topo maps, etc. (North/South position is just about perfect.) Any ideas on how I can fix this? Many thanks. (I wasn't sure where to place this question, so I went with GPS Units and Software. I hope that's OK.)

Not long a go, I got a Vista CX. Then, just the other day, I noticed an ad for the Vista HCx, for the same price. The company I got the Cx from has a 100% satisfaction guarantee. So I returned the Cx and got the HCx. The difference is amazing! Just a quick test of the unit reveals that the HCx unit gets a 3D fix almost instantaneously, whereas the Cx took about a minute and a half. Further tests are "pending", but a short excursion today revealed no issues. Highly recommended.