repeated system freezes starting today

[G.]

I received two separate updates.  One of them I noticed had some
updates for Chrome.  Since I installed these updates both Chrome and
Firefox have been freezing the whole system.  I have been forced to
wait a long time and then sometimes I get a script failure notice.
Sometimes I am forced to pull the plug to shut down.

Sounds like it could be a flash problem.  Any suggestions?

I am using Ubuntu 11.10 on a Samsung netbook with an external 21"
monitor.  I do not know what other info might be useful.

Thanks

garyk