Hello, I too have an Eclipse V4.01 and I started getting the Checksum Error, I replaced the battery today while swithched on and it saved my presets, BUT I still get the ” Internal Memory Checksum error” message along with “Press any key to continue”  after pressing a key the unit functions as it should. Do I need a downloadable fix ? Or is there a Fix I can do myself ?  I too am in the UK so it wouild be a real  ( and expensive ) Pain to have to return the unit to you..!!!!  Thank you in anticipation of your reply.