I do experience 404-errors on login (customer-login, not admin in backend).

This error does show up, when I do close the browser and start the browser again (FF as also IE) and the make a login.

The URL displayed in the browser with the 404-page looks like this: https://www.myshop.ex/?zenid=b7531b8...b7a73c643ca877

To get a correct login, I do now (after 404-login) have to browse through my shop a bit, then log out and log in again. Then the page shown is: https://www.myshop.ex/

Any ideas?

zc 1.3.8a
fast_and_easy_checkout_04022010155032_download 1.7.3