Grey boxes obscuring comments in posts with embedded youtube videos

Hi WP community – hoping someone can help me out here

I have a page with 10 youtube videos embedded in it, and when viewed in Firefox (my version = 2.0.0.12 on a macbook) at the bottom of the page in the comments section, large grey boxes youtube-sized boxes float on top of the text obscuring what’s written – I use a plugin to do the embed, but I’ve also tried it adding the embed code by hand and get the same result

The page (https://www.catsandbeer.com/music/the-top-10-rap-songs-white-people-love)
validates as valid XHTML 1.0 Transitional and looks fine viewed in Safari – all of the videos on youtube are active and I’ve even tried different versions uploaded by different users but the boxes remain (removing urls that contained hyphens as one person suggested might be causing the problem).

I’ve searched around and have found threads elsewhere of people reporting the same problem but didn’t find any solutions so I thought I’d try here

Another page on the site (https://www.catsandbeer.com/music/the-top-10-rock-songs-black-people-love-a-post-written-by-a-black-person) actually has more youtube embeds (12) but doesn’t have the grey box problem – perhaps the issue has something to do with the large number of comments & trackbacks on the first post (wordpress counts 437 as of now), but the second page without the problem also has a fair bit of feedback (102 responses) so that might have nothing to do with it

If anyone has experienced this problem and resolved it, please let me know, or tell me if there’s any other info I could provide that would be helpful

Thanks,

Brian