Using the repo found here:
http://github.com/nkallen/screw-unit
and this commit:
cc41f3cf373d804b11519704faf1971370f43760
I get this screen when viewing the package’s “EXAMPLE.html” file:

Basically all of the text showing how many tests were run and the describe/it clauses, and the test results are missing.
The same revision works fine on Safari and Firefox.
I found this report that seems related, but no follow-up:
http://groups.google.com/group/screw-unit/browse_thread/thread/f0e82f5d68acbf21
Any ideas?
Edit: I found that upgrading jquery from version 1.2.6 (included with package) to 1.4.2 results in a screen in which green/red tests show up. Unfortunately, the top header showing the number of total tests and failing tests does not show up.
Save yourself the trouble and use Jasmine. It runs on all browsers, offers custom matchers, works on all browsers, is offered by Pivotal Labs, and is wicked fast. Syntax is very close to Screw.Unit, so porting is not conceptually difficult.