XF 1.4 CSS in pages incorrect after changing templates

[Stuart Wright]

Folks when I make changes to templates, the first load of different page types is corrupted because the CSS isn't be loaded properly. Refreshing fixes it.
Members are reporting this issue so it's not just me.
We have a CDN working at static.avforums.com. And our css.php in the page_container is a relative link.
When I change a template, is the css.php called with new parameters or the same ones as previously?
Is this a CDN issue?

 

[EQnoble]

I don't know what you use for a CDN but wouldn't it be as simple as clearing or purging the cache @ your cdn for the related resources which were changed?