Combining CSS files (join_css=> true) not working

Hi, any ideas what could cause 'join_css' => true to not work? I just ported my site to a new server. Everything is working, except join_css. If I set it to true, it creates an empty joint CSS file, and still serves all the separate CSS files too. On my old server it put all CSS files into a single joint CSS file.

My old site had 38 requests on (as shown on My new site has 57 requests, seeing that CSS files are not combined.

It seems like it is still trying to create this joint CSS file, but it is empty. Using, I can see my new site serves an empty combined CSS file. I can also see this empty (0 bytes) joint CSS file in “cache/templates/css” folder. If I set 'join_css' => false, the number of served files actually decreases from 57 to 56, seeing that this empty joint CSS file is no longer present.

It is now working. When I access my site via IP address and username, it does not work:

Now that my DNS information has propagated, it works when accessing the site as:

So, seems like CSS join does not like IP/~username type notation.

Did you clear your cache after setting join_css to true? Sounds like a caching issue.