Error 500 after submitting

I've created a form using the tutorials on this website (which are very clear) and in large lines it works fine: it sends the data to the database and to the specified email address.
However after submission it does give an Error 500 message: no valid database connection.

I've already looked around the forum a little and came to this post: http://www.chronoengine.com/forums.html?cont=posts&f=2&t=3614&p=3892&hilit=submission+error+500#p3892

Tried the (perhaps somewhat outdated) suggestions: Turned off the validation and captcha, turned debug on and off, but so far without result. Mootools upgrade is also disabled.

I'm running Joomla! 1.5.22 and Chronoforms 3.2.0

I've put a backup of my form here: http://www.hermansr.com/backup-form.zip

The "working" form can be found here: http://www.hermansr.com/index.php/nl/jobs.html

Anyone any ideas / suggestions on what I'm doing/what's going wrong?

Hi Zassie,

The form looks Ok here and works OK on my test site.

The joom_ table prefix is unusual but there's nothing wrong with it.

I'm afraid that you have to contiue to test what is happening to pin down the precise problem.

First try disabling the ChronoForms DB Connection to see if that is at the root of the Server error.

You can also try turning on site Debug temporarily to see if that gives you any more clues (it may not). You need to find out which DB query is causing the error.

Bob

Thanks for the quick reply.

I was afraid that could be an answer... crap (I'm an absolute noob at stuff like debugging)

Will keep trying, thanks so far.

EDIT:
Turning off DB connection did the trick! it works like a charm. Even better because i really didn't need the stuff to be put into mu DB.

Thanks again!