This is exactly what's happening to my Magellan Triton 400. It'll power up fine. Then I go through the following steps.
1. Menu
2. GoTo
3. Geocaches
4. Select Geocache
5. Right arrow to select "I"
then just like you stated, the little radar icon thingy followed by the internal error message and shut down.
Any ideas on how to fix this? I've had to put my geocaching on hold because I like to have my Information to refer to.
I think I figured it out. Somehow, (not sure how) I discovered that when I select my geocaches from the list of "all geocaches" and then download them using the "download waypoints" button, something happens in the transfer...I think. Then when I transfer them from my VP to the GPS, I cannot access the "I" info on the unit.
HOWEVER, If I go to each individual geocache that I am interested in, and download the GPX from that page, I have no problems. It's just time consuming and tedious to get my geocaches that way.
Now, to figure out how to make this process faster and painless. Hmmm.