I have an answer to the problem with using Garmin Communicator to transfer waypoints to the GPS.
I have tested this on two machines and the problem (and solution) are consistent.
The problem is that, the implementations of the API to use Garmin Communicator are incorrect.
Garmin Communicator scans the USB string and identifies STORAGE devices along with GPS devices. It does not find my printer or scanner which are also USB attached. When the scan is completed the results are ALWAYS the same.
From the Communicator Test Page, all STORAGE devices are listed first by drive letter, followed by the GPS.
From the GeoCaching.com site, the initial download is automatically to the first device, the lowest lettered STORAGE device. The pulldown shows all of the devices listed but, selecting the GPS, doesn't help, the implementation at GeoCaching.com does another scan of the USB string and again picks the first device, a STORAGE device.
From the MyGarmin site, the GeoCaching download only chooses the first STORAGE device even though the page says that other devices are available. You don't get the choice to pick which one.
There are two way to overcome this problem.
1: As the user, with the GPS, you must NOT have any USB attached STORAGE devices so that the GPS is the first (only) device found by Garmin Communicator. This works with the Garmin Communicator Test Page, the GeoCaching.com site, and the MyGarmin GeoCaching download site.
2: The proper fix, for ALL users must be done by someone at GeoCaching.com to resolve the GeoCaching.com problem and at Garmin to rexolve the MyGarmin GeoCaching problem.
a: At GeoCaching.com, the implementation should respect the selection of the device by the user and NOT redo the scan for devices after a device is selected. This actually corrects TWO problems in that it allows the user to select a STORAGE device other thatn the first one and it allows the user to directly download the cache information to the GPS.
b: At the MyGarmin site, the fix appears to be more complex. Since they have not implemented the device selection function (which I believe is a mistake), they have to do a more detailed scan of the returned string/message from the USB devices and look for "GARMIN" to determint which device to send the information to.
I have spoken to Garmin Tech Support and passed this information on to the. I will also include this text as my final response to them.
I have not been able to identify anyone at GeoCaching.com or Grounspeak.com that admits to knowing anything about any of the implementations that are available at the two websites. Maybe this message will be passed on to someone or seen by someone that can address the problem at their end.