Yes, this is what I did, but the module does not appear on the front-end. If I make a menu item: content:tags/one and apply a module to that menu item, I can see the module on the front-end, but if I then edit the menu item to be: content:tags/one+two, the module disappears on the tag page.

Hello,
Find the module position where the module will be placed.
Try create a new menu item on a menu collection where it will point the url: www.example.org/tags/one+two

Finally visit the module's assignment tab of this module and select the menu item you've created above.

Webgift,
FYI, There is a problem with this module.
Exchange Rates
Could not parse XML File from cache

Open Shop updated to version 4.1. In this version a new payment method added named Paypal Checkout (paypalco) which is the newer Paypal integration method. With Paypal Checkout the payment is performed on merchant website without re-directing the user to paypal.com website. The customer can pay either by withdrawing money from his Paypal account (if he owns one) or by using his Credit Card. The old Paypal payment method which used the re-direction method is considered deprecated and Paypall will remove it soon.

So, if you use Paypal as payment method please switch to the new payment method Paypal Checkout and stop using the old Paypal method.

I just opened elxis.org with firefox, chrome and opera and loaded instantly without any delay.

thanks for the test