Safari 5.1 (OS X Lion) doesn't want to dynamically pick up styles?

Question

css

If you have Safari of this version, please try it on this page and let us know in the comments about the result. Thank you.
Yesterday I implemented the switching of the site's styling by replacing the style file. The task seemed to have already been solved when a colleague reported a bug - it did not change, the styles just flew off and new ones were not applied. It became interesting, because there were no problems in any other browser. It quickly became clear that the problematic machine was running fresh Safari 5.1. On other machines in Safari 5.0-5.3, everything worked out normally.
How does the method work? All possible variants of style files are linked to the HEAD section of the document using the LINK tag. The name of the current style is stored in a cookie. It is extracted by javascript and all LINK tags with unnecessary styles are disabled (blabla.disabled=true).
We have already applied another method, I would like to check: is the problem really in a particular version of the browser?
Thanks in advance.

Answer 1

Mac OS Lion, Safari 5.1.
Pressing Style 1:
Pressing Style 2 or Style 3 (there is no difference between them):

Answer 2

Safari 5.1: Style 2, Style 3 - styles flies.
The same Safari but with WebKit r93384 - styles are processed as needed.