Firefox 1.0.3 hates Flash, apparently.

I recently upgraded my system from Mandrake 9.2 to Mandr[ake|iva] 10.1,
which was an adventure in itself. Once I got it done, I installed Firefox
1.0.3. That went well enough; everything worked as it should.

Not content to leave well enough alone, though, I delved into the Mandrake
configuration tools and set up my Software Management tool to basically
"UPDATE ALL EVARYTHING!" (to paraphrase the ever-popular Zero Wing). All
the packages on my machine that had new updates got updated, successfully.

Obviously, I broke something. Unfortunately, having let it do its thing
automatically, I have no idea what.

Here's how the symptoms manifest:

Any page featuring Flash will either quit or crash a running Firefox.
Repeatable, testable, Flash is the deciding factor.

I have the latest Flash plugin. (7,0,25) I have the latest Firefox.
(1.0.3) Since having this trouble first crop up, I have deleted and
re-installed both Firefox and Flash.

So, I can only blame one of the packages that were updated. Are there any
known issues between Firefox 1.0.3, Flash 7, and any of the Mandrake 10.1
packages' latest versions?