I've seen all sorts of suggestions for dealing with the perennial problem with Garmin rubber surrounds coming loose - here's what I've done with mine, for better or for worse:

The black rubber bit started coming loose at the top after about a year. Even at this stage early it seemed a bit stretched. After another year it was completely detached, but I kept going for another 6 months just holding it in place. (This worked better than it sounds, as I mostly use the etrex for hillwalking rather than geocaching, and so generally walk with it held firmly in my hand). But gradually the band was getting stretched further, so I decided to do something about it.

After cleaning all the old glue away manually, I cut it at the bottom with a sharp pair of scissors, removing about 1/4" of length in the process. I tried sticking it back on with the glue from a bicycle puncture repair kit, on the grounds that that was designed for rubber too. It didn't work. Instead the rubber curled outwards hideously, and stretched even further; another 1/4" had to come off. Having cleaned all the glue off again, I thought of trying a sort of Bostick/superglue that was lying around. But I couldn't get any of that out of the tube, even with scissors, as it was all dried up. So in desperation I used the only adhesive that was left in the house - No More Nails. It worked perfectly, first time! Of course, having cut 1/2" off, it's now too short, so doesn't meet properly at the bottom. But the glue seems absolutely solid, and the buttons all work fine. So a success, of sorts. :socool: