Bought an Unlocked HTC Hero (UK) need Help!

[Guest cheezy_wotsit]

I bought a HTC Hero for my girlfriend to replace a hero that she lost, it was an Unlocked one and came without an SD card, I found an old micro sim that i had but it is only 512MB, but have formatted it an put it in.

Since putting her SIM card in the phone works OK, but it keeps coming up with an automatic update message.

If we click on 'update' it goes off and comes back with some messages along the lines of:

Build : RA-hero-v1.5

Finding update package …

Opening update package …

Verifying update package …

E:No signature (660 files)

E:Verification failed

Installation aborted.

and then takes me to a green stystem recovery screen, with various options, reboot device etc

I have no idea what to do with it, or what it means, i've been searching for stuff and keep reading about rooting & roms etc but i really dont know what that all means and really dont want to mess the phone up.

Do i need to get hold of a different SD card with the correct data on it?

Any advice would be greatly appreciated, i'm kind of wishing i'd not brought the phone now!

Thanks