I am attempting to track order from Ebay.

The seller should have provided you with a link and or tracking number. How is this a browser issue?

Could you describe where the process is breaking down in a little more detail. For example:

Did you get a link directly to a delivery service, or is it a link to an eBay page, or does it go somewhere else (like a bulk mailing service)?

Does Firefox display any error message, or does it stop somewhere in mid-process? Do you just get a blank page?