I have a 60CSx that WebUpdater 2.4.1 would not update past 2.90 for the G chipset. Garmin does not make 3.00 available on their website, but one of their engineers directed me to http://www.gpsinformation.org/perry/agree.html where I could download it. I grabbed GPSChipsetTypeG_300.exe and GPSMAP60CSx_370.exe from the gps60 folder. I don't recall which order I installed them in (it only worked in the right order), but it worked great for me. Lots of other Garmin updates there too for other units.
And since I'm on FairPoint, my IP could be from China too...