-> Tap ALT key or press F10 to show the Menu Bar

-> go to Tools Menu -> Options -> Advanced -> General section -> Remove Checkmarks from :

1) Always use cursor keys to navigate within pages

2) Use autoscrolling

place Checkmark on Use Smooth Scrolling

-> click OK

Check and tell if its working.

Thanks for your suggestion mha007, but it did not work. I am still able to virtual scroll on pdf files that are opened in Firefox or if use another browser like Internet Explorer.

try this:

-> Tap ALT key or press F10 to show the Menu Bar

-> go to Tools Menu -> Options -> Advanced -> General section -> place Checkmarks on:

1) Always use cursor keys to navigate within pages

2) Use Autoscrolling

3) Use Smooth Scrolling

-> click OK

Check and tell if its working.

You can try to set the pref ui.trackpoint_hack.enabled to 0 or 1 on the about:config page to see if that makes it work.

To open the about:config page, type about:config in the location (address) bar and press the "Enter" key, just like you type the url of a website to open a website.
If you see a warning then you can confirm that you want to access that page.

• Use the Filter bar at to top of the about:config page to locate a preference more easily.
• Preferences that have been modified show as bold(user set).
• Preferences can be reset to the default or changed via the right-click context menu.

It did not work.

-> Tap ALT key or press F10 to show the Menu Bar

-> go to Tools Menu -> Options -> Advanced -> General section -> Remove Checkmark from Use Hardware Acceleration when available -> click OK

Check and tell if its working.

It does not work.