Sudden changes in theme..what’s causing them?

Hi,

Some parts of my theme have started showing up wrong all of a sudden. For example, you can see from this screenshot… https://i11.tinypic.com/5x98o3t.jpg …of a cached page from google that the post titles aren’t underlined, the categories are a pink colour and not underlined and the no. of comments are also a pink colour and not underlined.

That’s how it’s supposed to be but its changed for some reason.

It seemw to affect everything starting from no. of comments on the first post right down to info at the bottom of the page.

Also I’m now getting 10 errors in validating my page as XHTML 1.0 Transitional whereas before I had none and I’ve changed nothing.

Anybody know what’s going on?

Thanks