Which SD card for TTOne v1?

[Windymiller]

I tried putting a 4GB SD High Capacity Memory Card (Jessops) in my TT and it wasn't recognised? Is it too large?

[Windymiller]

The bugger! Cheers mate!

[Windymiller]

Could I used one of the micro-SD cards that come with an SD adaptor? Can't seem to find anything but those!

[Windymiller]

Here's another one... are Tom Tom maps unit specific? Not just model (ie, TT1v1, TT1v2, etc) but actual serial numbered unit specific? Thanks!