Adobe Flash Player constantly crashing when exiting in Mozilla Firefox

Hi

If I use a flash object on a website that requires Adobe Flash Player, then leave the website by closing the tab or the browser, it will freeze up (Mozilla Firefox) for anything from 5 seconds to 5 minutes, during the time it freezes my CPU usage drops but memory usage remains the same until I get a popup saying:

" Shockwave Flash may be busy, or it may have stopped responding. You can stop the plugin now, or you can contniue to see if the plugin will complete. "

I have 2 options, Continue and Stop Plugin

Pressing Continue will make the browser freeze for longer but will eventually unfreeze itself, pressing Stop Plugin also freezes for a while longer then gives me the usual " Flash Player has crashed " message asking me to send a report.

I have completely reinstalled Mozilla Firefox and Adobe Flash Player many times, enabling and disabling hardware acceleration in both Mozilla Firefox and the Adobe settings. I have tried this on another user account on my machine with fresh installs of Mozilla and Adobe resulting in the same crashes.

Here are my system specs.

Vista Home Premium SP2 (32bit)

Intel (R) Pentium (R) Dual CPU T3200 @ 2.00GHz 2.00GHz (2GB of RAM)

Mozilla Firefox: 37.0.2

Adobe Flash Player: 17 NPAPI (17.0.0.169)

A screenshot of the popup crash message: Screenshot by Lightshot

I hope I haven't missed anything, please help

Thank you,