MacBook OS 10.7.5, running Firefox. Invisible Cursor...

MacBook OS X (10.7.5), running Firefox 18.0.1 (although I think this has been happening since OS X Leopard + Firefox)

While streaming video the cursor becomes invisible, but still moves & functions correctly.

While the cursor still works, I find it very difficult to work w/ an invisible cursor.

SImilar issues? Solutions?

Thank you

*I imagine it has to do w/:

(a) my Firefox plugins &/or extensions..

(b) my graphics or media drivers..