Site won't load CSS until reload

I can't get my CSS to load correctly, upon initial visit to a Zen product category, until reloading the/any browser.

The path which loads style-less: /index.php?main_page=index&cPath=128_129_131

Upon reload, though, it's fine.

I am NOT going to this path via Zen-Cart, if that matters. I'm handing off to that path from a seperate HTML page.

I've solved this, by (yes, according to the FAQ) turning .htaccess to htaccess_OFF in /includes and /admin/includes.

Jumping to a page within the Zen install now works correctly, with CSS loading according to plan.

I'm at a loss to explain how, though, the site itself, when entered via the main index.php page loads all pages correctly; it is only when attempting to jump to an internal page the issue presents itself.

And, of course, now I need to run the site without htaccess precautions in place. Make of this what you will.

You could disassemble your .htaccess file piece by piece until you determine which element is causing the problem.