A few comments:
- It may be something odd about the exact format of jbensman's imagery that may be causing the problem. If you (jbensman) could send one of your bad KMZ files to somebody else to try on their Garmin, and concurrently get a high-res file created by G-Raster and known to work to try out on your system, that might help in figuring out what's going on.
- Didn't know about the problem with non-alphanumeric characters and spaces in filenames. Just released 1.5, and pulled it back to fix that issue. Oddly enough, like GlobalMapper, I'd been using "_" in the jpg filenames without any problems, but I've removed them from those files too just in case. Non-alphanumeric characters are now automatically pulled from all filenames. If that's the problem, the latest version should fix that.
- The problem with not resizing when the number of tiles is greater than 100 is driving me nuts - sometimes it shows up, other times it doesn't, and with the same image file. I'm working on it ...
- The default JPG quality factor for G-Raster is 80, which should result in a 100-JPG-tile filesize of roughly 35-40 MB or so. But I think maps4gps may have been talking about the original GeoTiff filesize, not the KMZ filesize.