The date display will be determined by the regional settings on the machine you are viewing the page through, not that set for the server.
Grr...just been and tested this and you're mostly correct.
I'm primarily a Mac user (with Safari 4.0.4 under OS X 10.6.2) and although my system knows it's in the UK and is set to use UK date, time and number format, Orion's Web console doesn't reflect this. Same goes if I'm using Chrome or Firefox on the same machine.
Fire up my Windows VM and it works perfectly in IE.
This is a real pain as no one in my team uses Windows unless they absolutely have to (we're all Mac or BSD/Linux). We bought into Solarwinds as it offered (what seemed like) comprehensive web access to the system but we're slowly finding out that you still need to be running IE on Windows for it all to work properly.