what will happen if i disable paypal express checkout?

[tesefoti]

I've been using Paypal express checkout for a few months and some clients used this option.
The problem is that now I added the state field as mandatory in order calculate shipping and Paypal express messes up the state field because sometimes it has special characters like ç or à. it changes to non existing state with weird characters like ã and it doesn't calculate shipping so he can't finish the order.
i was planning to remove paypal checkout express but now I am hostage of it because some clients bought through it and they don't have a password for their account.
is it possible to fix this and do you think it will be fixed if i change to paypal IPN?
i don't want my clients to go and express checkout without opening a account with me, with date of birth, password and drop-down for state, etc. i feel that currently the client belongs to paypal. thanks

[CoolCarPartsOnline]

Express checkout uses Zen Cart to calculate shipping. The issue could be due to template or coding errors. I don't see a link to your site so I can't guess what's wrong with your template.