When opening Firefox one of my homepages is often replaced by the new tab.

Question

For the last several versions of Firefox one of my two homepages on opening the browser is frequently replaced by a new tab; clicking on the home icon always opens the missing homepage (along with a second copy of the other one that is open), but this is now getting annoying. I was hoping an update would fix the problem, but of course this has not happened.
The problem began several FF versions ago just about the same time I updated CCleaner, so I considered the possibility that the latter was deleting something that interferred with my FF tabs; after having uninstalled that version of CCleaner, however, and reinstalled the previous one - the use of which had never coincided with the tab problem - the continued issue with the new tab was clearly not due to CCleaner, so I could only assume that the problem was with FF itself. (Note: I had not installed any new plug-ins or extensions at the time the problem began.)
Thanks.

Answer 1

Hello All.
I cannot be sure if it is related, or indeed is the cause of the problem with the new tab, but in the last couple of days it has become evident that Google has been modifying some pages, including the Gmail logon page.
1) Yesterday I found that on the logon page the field for the password had gone; the username field was there with a blue button below it saying 'Next', which I had to use to bring up the password field;
2) Today, after attempting to login to my e-mail, I was taken to a security checkup/update page for my account, which I completed - except for providing a 'recovery phone number' - but I was given no way of getting into my e-mail; if I logged out and in again I was again taken to the same security update page. Eventually, I went to a google support page via a search engine and saw a link for Gmail that took me straight into my e-mail - I was still logged in - and I replaced the Gmail address for my Firefox homepage again and now I can get into my e-mail. (Part of my problem here may have been that I refused to give a phone number; the form asked me to complete it by adding a number, which I would have to have verified so I could not fake it, i.e. 01234...)
Given how long I have had the new tab problem - since at least FF32.0 - Google may not be the problem, but changes such as I have described do sometimes take some time and can clearly cause problems. Are any of you Gmail users?
Ian.