I've tried to change my main domain from presario.x10.mx to fbapps.org.uk and I get this error when I view pending actions:

Hosting Domain Modification
submitted March 20 at 1:55 pm
7aVlcx9UcXd1
action status
Error
information
A change to your hosting account's primary domain.
result
A system error occurred while processing this action.

Error Code: C085843B

I have set the nameservers of fbapps.org.uk to yours.

Can you find out what's wrong? Thanks.