Error when adding item to cart

[Sabine_in_MG]

I'm setting up shop - it's live but I haven't had a "grand opening" yet :)
Anyhoo, things are going well, I dug my way through the great forum and the helpfiles to configure the setup and look/layout.
Everything was working fine, then
When I click on an item in the shop I receive an internal error message

[Tue Apr 29 12:53:35 2008] [error] [client 74.46.192.249] File does not exist: /home/designv6/public_html/500.shtml, referer: http://www.designswithheart.net/shop...roducts_id=187

on this particular page

but also when trying to add any other item in the store so far .....

:) at least it's only a few "test" items and not a fully stocked inventory !

Any help would be greatly appreciated, I'm at a total loss as to what could cause this.

Thanks bunches!

Sabine

[Sabine_in_MG]

never mind I'm re-installing from scratch - urgh