checkout error joomla 1.5.15

[annabronwyn]

using virtuemart2 and joomla 1.5.15.  i'm getting a "problem loading page" error whenever i try to check out.  it happens whenever i click any link in the shopping cart, including the link in the sidebar to get to the shopping cart (you can only get to the shopping cart when you click "view cart" in the pop up window that appears after you add something to the cart. 

i've uploaded both virtuemart 2.0 and virtuemart aio, but i uploaded the aio a day later than the original file i think.

here is the website in question: evansteelperformance.com

hopefully i haven't reiterated a previous query, i did do a search but couldn't find my exact issue.

thanks in advance for any advice!

[jenkinhill]

VM2 has not been tested on that old version of Joomla, suggest that if you are staying for the moment with J1.5 that you upgrade to 1.5.25.

The aio should be installed immediately after the main VM2 component.