I've been looking at getting a 4GB micro SD but all I seem to find is micro SDHC.
I have read other threads saying SDHC doesn't work with Windows Mobile 5 but does with Windows Mobile 6. Can I upgrade for free?
Virtually all cards above 2GB are SDHC (but 4GB SD cards are rumoured to exist...)
I had an M3100 until recently (RIP, poor thing) with WM5, and it didn't support SDHC.
You could try upgrading the ROM (which would void your warranty) - there's loads of confusing options at forum.xda-developers.com - or you might try this patch
which some people seem to have had success with on WM5.
Upgrading ROMs is free, but of dubious legality at best...although you run a slight risk of permanently breaking your phone, it's a fairly straightforward process (google mrvanx for a guide).
Edited by fraktal, 21 July 2008 - 12:54 AM.