OK. Just read my reply and seems a bit ambiguous.
Lets keep it simples.
1. I use Webmail in business and I access it normally through a PC, netbook etc.
2. I access the account on my mobile using Andriod stock email client. I set it up by listing server details and passwords etc.
3. All had been working well until this morning when I changed the password for my Wife's email account.
4. I can access the account with no problems via webmail on a PC, netbook etc.
5. I changed 4 others with no problem.
Hope that clears it up.