Orderproblems with several payment methods

[jagge]

Hi there all,
im experiencing a very strange behavior in one of my stores on 1.3.9h.

Sometimes using a credit card module the transaction is going through but theres no order i zencart admin? This happens 1 of 4 orders.
First I thought problem were something in the module BUT sometimes even moneyorder is not working.
When clicking confirm order it just bouncing back to checkout. No order and all products still in cart??

So now im suspecting bigger issues. Does anyone have any ideas of what might be causing this?
I have normal session settings in admin.

Some extra modules is installed:
Edit Orders
Stock by attributes
SEO Urls
Google Analytics

/Jagge

[Kim]

If you turn off the SEO URLs do things work?