bg-foxx:
I had the same problem, but when I unchecked the Core: Default: Skip SSL from the admin->SEO URLs-> URL plugins it started working fine.
Now, I have a problem with PayPal IPN. It's throwing me to their home page instead of the page where customers can actually buy. It works fine when I disable SEO URLs.
I'm digging to find a solution to this, but no success thus far:(
I've been testing this SEO mod for a couple of days. Just tried it on prommart.com (1.3.6) as it is PayPal only.
I also was taken to PayPal's homepage during test checkout. I fixed that (as I recall) with Step 3b in the installation instructions/pdf after pasteing the alternate code in the .htacess. It took me to the proper PayPal checkout area.
Still had a problem. While the test order went through at PayPal, it did not come through to my ZC admin, nor did I get an admin email notification of the order. This is the final hang-up and I have disabled the SEO mod for now. Had to take the inserted code out of html_output.php just to get PayPal working again.
NOTE: The other day we installed a commercial SEO mod on findmypromdress.com (uses authorize.net). It works.