"spanish" accents (e.g. ?, ?, ? , ) in clients module

Hi

I just downloaded a 35 day trial of nBill (v 1.2.2) runing on joomla 1.5.7 in spanish from joomlaspanish.

I'm having problems with accents when filling up info on forms in the backend.

When I edit or add a new client and use accents this happens:

1. The accent shows ok in the form field (e.g. I type "Calder n") and when I save the client and return to the clients list everything from the accented letter to the right dissapear (only shows "Calder").

2. If I use the "ó" when I type the name (e.g. I type "Calderón"), when I save the client and return to the clients list the accents show ok. That would seem to fix the problem but is a pain in the neck to have to do that hundreds of times and ...

3. I got into the `jos_inv_client` table and in the field where I used the accent it shows cut (only shows "Calder") and where I used "ó" the same chars are in the field (it shows "Calderón")

4. If I edit the field in PHPmyadmin and type "Calder n" it shows ok when I save the changes but it shows "Calder�n" in the clients list and shows nothing in the field if I edit that client.

I don't have any problems with accents in any other module.

I'd say that since the BD tables accept the accents it's a utf vs iso char encoding issue in the PHP scripts (if words are written cut to the DB, then the problem is there) but couldn't check because they are encrypted.

Thanks for your time