Hi guys,
sri lanka, IMG, file, is working, Install garmin map source to your PC first. Then install the Sri Lanka Map.exe , (you will find a standalone installer with a complete map of Sri Lanka) and when you are prompted, ckick YES for "update garmin mapsource". After map installation is complete, open Garmin map source. You will see the installed map in "Map list".
If you can view the map on garmin map source, just plug the GPS to your PC, and click "Send to Device". Its working fine for me.
Aruna