http://prodemo.splunk.com/ l:guest p:guest They know they're not safari compatible at least.
The first thing I noticed when loading the URL is that a JavaScript exception is raised before the page completes loading. This is also visible when viewing their unauthenticated demo at <http://demo.splunk.com/>. It will require a reduction and further analysis to determine the cause of the problem.
Logged in, not reproed any issues, works for me. Please reopen if you can repro any specific problems.