Theres an age old question, i found my issues almost evaporated when i started to use the 64 bit flash and browser on my 64 bit system. I can use any browser now as long as it uses the 64 bit flash which all browsers will not.
Only time i get problems is when i start mixing 32 bit and 64 bit stuff during the same computer on session and flash will crash.
I also found various browsers install various versions of flash.
Here is what you might try.
Uninstall all browsers but 1 realizing IE cannot be uninstalled you might end up with 2, but IE now uses a built in flash player upgraded by MS so it's built in and walled up.
The 1 you pick should be optimized for your set up, 32 bit or 64 bit. 64 bit systems are picky but will run 32 bit but run 64 bit far better and run 32 bit poorly.
If your system is 64 bit, make sure you use a 64 bit browser and 64 bit flash.
Type msconfig into run and shut down all those services calling home and do not let them startup. google is needed here.