I have a 660LM that I went to update this morning. It told me I didn't have enough space, so I replaced the 4gig card with a 16 gig (empty) card and pointed it towards the SD card for map installation.
I've now been sitting at Step 3 of 3 for over 30 minutes and the bar hasn't changed, there's no projected timeline, there's no %, nada.
I hesitate to disconnect it since I don't want to brick my Garmin. This thing is awesome.