Re: the page numbers on my e-mail are missing, how do I get them back?
From your description, I understand that your webmail provider used to display 25 emails per page, but now it is showing all the emails in a continuous form, where you can scroll down the page.
It appears that your webmail provider is Yahoo!, is this correct?
Yahoo! recently redesigned their webmail, and it is the only version available to users, so there is not much that can be done. Please understand that this is not a browser related issue, so Firefox is not at fault.
Please see this link for more information about the Yahoo! Mail redesign.
I hope that this information is useful. Please let us know if you have any other questions.
Start Firefox in Safe Mode to check if one of the extensions (Firefox/Tools > Add-ons > Extensions) or if hardware acceleration is causing the problem (switch to the DEFAULT theme: Firefox/Tools > Add-ons > Appearance).
Do NOT click the Reset button on the Safe Mode start window or otherwise make changes.