Will uppercase closing script tag 'break' a site?

I'm trying to help a web developer I'm working with figure out what might be causing poor rendering of a site I'm helping with. It involves javascript with rotating images, and the site is all skewed at different times for different people using different operating systems and different browsers (I just checked that via browsershots).

She's been trying for quite a while to fix it, and it's pretty urgent now, so although I know next to nothing about creating or troubleshooting ja开发者_如何学Pythonvascript, I decided to have a look via w3's code validator myself to see if a second set of eyes might help, and I see that a closing script tag is in upper case letters, and w3 says only lower case is allowed in xhtml. I haven't heard back from the developer yet, so, I'm curious about what others would have to say - would this 'break' the site?

And what about having duplicate content-type meta tags - there is one above the title tag and again below it - both the same. Would that be having any effect on anything on the site?

I'd appreciate any opinions or advice. Thanks in advance.

Neither problem will break the site, unless you are serving the page with an XML content type, and you almost certainly aren't. But I endorse Pete Wilson's comment. The starting point for fixing (X)HTML problems is to ensure that the page validates.