ie and the 30 css files limit - how merge css files

Go to admin/settings/performance and enable "Optimize CSS files"

Please try the hook_preprocess_page() code from http://drupal.org/node/228818#comment-1473586, I've used it in Zen v6.x-2.x-dev to great effect.

This is the same issue as #256802: IE limits Drupal to 31 stylesheets total.

Apfel007, don't use the code pointed to in comment #3; its buggy.

Instead try this module: http://drupal.org/project/ie_css_optimizer

John: With all due respect, that module is going to pose more problems than the simple code snippet, which has proven reliable in my tests.

I have tested the code snippet. Its extremely buggy in that it doesn't deal with overriding and removing module or base theme stylesheets. If you copy a stylesheet from Zen and put it in your sub-theme using that snippet, both stylesheets will be included on the page instead of just the sub-theme's version of the stylesheet. ick. I should have mentioned that in my previous comment. Sorry about that. :-)

And I don't see how the IE CSS Optimizer module is going to "pose problems". If there are issues, please post them to http://drupal.org/project/issues/ie_css_optimizer

Apfel007, yes, that's correct. CSS aggregation doesn't work with private files. :-( And the ie_css_optimizer module just modifies core's CSS aggregation functionality.