Sounds like you may have inadvertantly or otherwise installed something that is affecting firefox. It may help if you attach a screenshot of the message with your next post.

• see how do I create a screenshot of my problem?

See also

• searches are redirected to another site <-- clickable links (blue) --
• is my firefox problem a result of malware
• troubleshooting extensions and themes

I also suggest you try the CAPS LOCK

What is it you are using that is causing this problem Babylon ?

Here's a few other thoughts about that issue:

1. Firefox doesn't detect and block attempts to change the Homepage setting as Firefox is launched. You probably have a security program installed that is giving you that message.
2. Only malicious applications would try to change a user setting, so nothing should even be messing with your choice for the Homepage setting in Firefox Options > General.