When I try to unlock maps the wizard tells me error communicating with GARMIN server

Map unlock codes are specific to each unit. You will need to contact Garmin to obtain a code to unlock the maps.

I think this one is a return to seller or send to Garmin.

You have use the unlock wizard to install the key that is provided with the software. When I bought my Mapsource CitySelect, it came with two keys. The way Garmin does it is, you can install the software as many times as you want on as many machines as you want, but can transfer the maps, data, etc ONLY to unlocked devices. Last I checked Garmin wanted $75 for additional unlocks. Some data is not locked, like Topo maps and some tide points since this data is obtained (by Garmin) from the gov't, which is free for us (wel, minus taxes we pay). Contact Garmin support, they are very attentive.

Install the Garmin City Navigator Cd to your pc and then connect ur garmin to ur pc with the USB cable.
You might have to unlock the maps with information provided with ur garmin like ur unit ID and ur unlock code.
Another possiblity is that ur memory card is gotten corrupted so try installing it on a different micro sd card.
Let us know if u have any luck.

This means that there is an error with the data on the CF card..Try reloading the maps another time..

Fixed. Called Garmin. It seems that version 4.90 FW on the Nuvi 350 (which came shipped on my 350) has a bug where it cannot communicate with the Garmin software either to update maps or update FW. Tech from Garmin e-mailed me a patch that I copied into the Garmin folder on the Nuvi itself, via USB and Windows Explorer. I then rebooted it; the patch installed itself which then allowed the unit to communicate with the map upgrade software and all is well. 2009 map update is now installed and the Nuvi is working fine again. Haven't tried upgrading to newer FW yet; will probably leave well enough alone.

Open C:\garmin directory then right click on the .exe file "Unlock wizard". Open this file as administrator and behoild it works. Even though you may already have full administrative rights as I did.

Does it recognise the Nuvi? Are you connecting it through a usb Hub. Are the drivers for the nuvi installed properly? Usually there is a folder named USB, thats where the correct drivers reside, and that's where you tell the computer to look when it asks for the drivers.

A way around this is to insert the SD Card into the computer (SD Card reader), point the directory to the card and install the maps like that. I had to do that the first time I bought my unit because I couldn't figure it out and got frustrated. So I thought of this easy work-around.

i dont think you can upload maps to an i3, it can only load pre-loaded maps on micro-sd cards.