>I changed back to the english interface and I get no errors. I guess you could test this by changing to the spanish interface and trying to go to the private messages. I've been selecting "No" to the question if I want to debug, I suppose you could see the code when using the spanish interface to see what is causing this error.

Yup, two messages have been entered with carriage returns. I removed them from the translation table (the carriage returns) and it is now ok.