Is your flash player up to date?
to test it and check the version.
10.3 is the latest version
You can get it here:
I would update it if you have anything below 10.2
Flash objects are active, and could cause a browser crash that normal picture files would not(jpeg, gif, png, etc...)
If it locks up during the test...or you have trouble installing the newer version, you can get an "un-installer" here:
then just re-install it using the above installer link