• Does the problem happen with another computer?
• Does the problem happen in Diagnose Firefox issues using Troubleshoot Mode?
• Does the problem happen in a new profile?
• Does the problem happen when security software is temporarily disabled?
• Does the problem happen with Internet Explorer as well?

Hi Jan,

Thanks for the reply. To answer your queries:

• The problem doesn't happen with another computer (my netbook).
• The problem does happen when I Troubleshoot Firefox issues using Safe Mode.
• The problem doesn't happen in a new profile.
• The problem does happen when security software is temporarily disabled.
• The problem doesn't happen when using Internet Explorer.

Your troubleshooting questions would therefore suggest that there may be a problem with my existing profile?? Although I'm not sure what would be the cause. I am loathed to replace my profile as Firefox is set up nicely (apart from the startup problem!!)

Not sure where to go from here?

Go to about:config & verify the following. browser.startup.page should be set to 1 instead of 0.

You can also control this from a mozilla.cfg file with the following pref.

lockPref("browser.startup.page", 1);

When exiting Firefox, to prevent this from happening, you can exit Firefox by going to the Orange Firefox Menu (or File button) and clicking 'Exit'.