@connexhosting:
I can send you my latest version I have if you like, so you can comapare. I never use msn or anything (for free support) though, this already takes way too much of my time as it is now ;-)

@walter:
Fatal error: Call to undefined function: display_price_nosymbol()
The version you have requires some changes to be made to the currencies class file. The error shows that your currencies.php file does not include these changes (a currencies.php isincluded in the zip).

Actually I think you better try the latest version attached to this thread (1.2.3). I have not tested it on 1.2.x versions but I am quite sure it works without any modification.

I would like to upload that newer version to de Zen downloads section, but I am waiting for at least one positive response that that version works without problems. Not that I expect any problems of course :-)

Illegal Access
If this is not happening because of something you did yourself recently, and you can't find the cause, I think you better talk to you host about it. It looks like an .htaccess issue or some hosting panel ip-block.