Mouseovers not working

[Jimi King]

Would some kind soul please have a look at the attached. I'm clearly having a senior moment here (they are becoming more frequent these days).

I'm designing a website for one of my Internet radio channels and I just tried a web preview of it and none of the mouseovers are working, including one that is actually a link (the PLAY button). I can't for the life of me see what I've done wrong.