Pretty much what Flamey said.
The only thing I don't bother validating 100% is my CSS code, since I intentionally have to break the rules with it using some hacks just to get my stupid pages working right in InternetExplorer.....
Regarding yer td background, why not just add a style tag for it to your CSS code if you need it? I'm a bit of a standards whore (aside from CSS for noted reasons), so I always check my pages for 100% compatibility (I use XHTML1.0 Strict), just to ensure I'm doing things the way the standards were defined, it's just unfortunate that a specific company and web-browser that doesn't need mentioning requires some extra tweaks to get said proper code working correctly.
The only thing I don't bother validating 100% is my CSS code, since I intentionally have to break the rules with it using some hacks just to get my stupid pages working right in InternetExplorer.....
Regarding yer td background, why not just add a style tag for it to your CSS code if you need it? I'm a bit of a standards whore (aside from CSS for noted reasons), so I always check my pages for 100% compatibility (I use XHTML1.0 Strict), just to ensure I'm doing things the way the standards were defined, it's just unfortunate that a specific company and web-browser that doesn't need mentioning requires some extra tweaks to get said proper code working correctly.