Somehow php broke doctype

Question

I created two threads here and here about that internet explorer works in quirks mode and that broke the layout. After a bit of investigation I found that somehow php make s

Answer 1

Most likely there is some output going to the browser before the doctype.

Ensure that:

• There is no white space or any other kind of data before the opening tags
• There is no BOM at the beginning if your files are saved using some Unicode encoding

...in any of the files that are being parsed to generate your output.