Replying to Video and link embeds aren't working?

Whenever I try to embed a video (I click the little flash button and paste in the embed code as usual) the "add video" button on the bottom of the pop-up window refuses to work. Also, as of some time today the button to embed/make click-able links will not work at all. It doesn't even give me the little pop-up window. could this be because I'm running Mac OSX 10.5? I have tried clearing my cache and all that jazz.