If you visit a page you've never bookmarked and click the star, does it turn yellow? Then the problem occurs when you click it a second time to move it to a folder?

Does the same problem occur when you press Ctrl+d to create the bookmark?

Could you explain the scrolling in a little more detail: are you scrolling the folder list using the mouse wheel?

I wonder whether any of your add-ons could be interfering? A standard diagnostic for that is to try Firefox's Safe Mode.

First, I recommend backing up your Firefox settings in case something goes wrong. See Back up and restore information in Firefox profiles. (You can copy your entire Firefox profile folder somewhere outside of the Mozilla folder.)

Next, restart Firefox in Firefox's Use Troubleshoot Mode in Firefox using

Help > Restart with Add-ons Disabled

In the Safe Mode dialog, do not check any boxes, just click "Continue in Safe Mode."

Any luck?

Try to disable hardware acceleration.

• Tools > Options > Advanced > General > Browsing: "Use hardware acceleration when available"
• https://hacks.mozilla.org/2010/09/hardware-acceleration/

If disabling hardware acceleration works then check if there is an update available for your graphics display driver.

• https://support.mozilla.org/kb/how-do-i-upgrade-my-graphics-drivers

Thanks a lot cor-el... I followed the steps and updated my graphics driver that fixed the problem.. i think the entire issue was because of a issue with the Graphics Driver update last month ... Once again THANK U !!!!

You're welcome