This is hard to answer without seeing the site. If it is a public page, can you post the URL and describe the steps to recreate the problem? If it's a site you're developing that isn't online yet, maybe you can describe the scenario in more detail or post a stripped-down test case.

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

In the code its alright. If i inspect the code its showing the correct value selected but its not reflecting on the page.

Let me see whether I understand your scenario. You are not changing the <select> control interactively with the mouse or keyboard. Instead, you are changing the value of a <select> control in JavaScript, and the control itself is not reflecting the change.

What is your code to change the value of the <select> control? I find that setting the .selectedIndex property usually works. The script at http://www.jeffersonscher.com/thailan.../food/ uses that technique when you use the left or right arrow to navigate to previous or next photo. Does it work on your Firefox and Chrome? (Press t first or click the Tools button to clear the overlay.)