Help with Mapsource Routes to Garmin C340, C530

Hi. I'm trying to get an understanding of what's possible with Mapsource and my Garmin C340 and my friend's Garmin C530. I've searched and read posts all over the place until my eyes are blurry and I'm still confused. I was directed to this forum by some kind folks in the Garmin newsgroup. So here I am with hat in hand looking for assistance.

The point of contention is whether routes created in Mapsource can be downloaded to these devices.

Both devices have the latest software. Mapsource is installed and the 2008 North America maps are unlocked for each device. Both devices communicate just fine with the PC.

With the C340 the Routes check box is disabled when I try to send to device. I asked about this in the Newsgroups and was told this is because routes cannot be downloaded to the C340. For this device I'm just looking for confirmation that what I was told was correct.

For the C530 Mapsource behaves differently. After creating a route the check box is enabled for sending to device. I send the route to the device. It says it's successful. I see a temp file on the device. After turning on the device I cannot find the route anywhere. Not under favorites or recent trips or anywhere. Yet when reconnecting the device the temp file is gone. So the device knows it's there and is doing something with it.

What I need to know is if the route is actually being sent and if so, where is it?

Thanks for any help.