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.

• https://support.mozilla.org/kb/Safe+Mode
• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes

Also make sure that your firewall or other security isn't causing this problem.

Thanks for answering. I tried it in safe mode and it still didn't work. I disabled the only add-on I had and disabled the hardware accelerator and it still didn't work. I was already in default theme.

Can anyone tell me how to check my security and firewall? I don't know how. I have windows 7.

There is usually a button to refresh the CAPTCHA in case you can't decipher it. Did you try that?

Also make sure that you aren't blocking cookies.

• http://kb.mozillazine.org/Cookies

Thanks again.

No, refreshing the CAPTCHA doesn't help. I can usually see them okay anyway.

As far as I know I'm not blocking cookies on any websites. I checked just to be sure, but no, I'm apparently not blocking cookies.

Any other suggestions?

I have had this problem for a couple of months now as well. I use Firefox 18.0.1 on a Macbook Pro 10.8.2.

I have no problems at all commenting on Blogger blogs using Safari or Chrome. Only Firefox. The thing is I like Firefox best and would like to the ability to comment on blogs using it - I could do so in the past with no problems.

Thanks