Yeah I usually have to "game" the system. For one thing I keep my wish list open in two separate browsers and two different windows. I submit in both, then open up new tabs of the same page in both. I never "refresh" unless I have an active window somewhere.
The gencon webpage seems to be (and always as been) optimized for IE so if you're trying this in FF or Chrome you're at the very least lagging a few seconds behind IE users (I've tested this for a number of years), which can be crucial.... as you're learning.
Then resubmit your wishlist even after paying for your cart items...you never know what will be released two hours from now.
I had windows in 3 different accounts in Firefox, Chrome, and IE this year (my brothers were at work and had me check out for them).
I clicked submit in the IE window first.
The IE window came in 500+ slots further back in line than the other two.
So - I think you're fitting a pattern of IE superiority where there is none.