Pages rendering as source code

I have a major problem which suddenly occurred yesterday on a site that has been running OK for months. Certain pages are rendering as plain text source code rather than html. I do not think I made any dramatic changes recently to cause this.

Looking at the headers in Firebug it says that the Content-Type is text/javascript (rather than text/html on working pages) and the console gives this warning: "Resource interpreted as Document but transferred with MIME type text/javascript".

The server administrator suggested that it might be a problem with Community Builder. I have upgraded this morning to CB 1.8 but the problem persists.

Can you help? I am on Joomla!1.5.

The server administrator suggested that it might be a problem with Community Builder.

Is there any basis for this claim? It's rather bold with no proof or debugging information. I don't see how or why CB would do this.

As far as I am aware this can only happen if for whatever reason there is an unclosed PHP tag perhaps or there's a system plugin that's altering the buffer. Try disabling 3rd party CB plugins 1 by until resolved. If not then repeat with Joomla system plugins.

More details on what pages exactly are doing this would also be of help. Review the code that is rendered raw and see where it's coming from will also give clues of what's causing it.

I honestly did not mean you to read "suggested that it might" as a rather bold claim!

Thank you for your pointers, I will follow them up.