It sucks that people are having issues, but this pre-sale is way better than other bands, for example the Tragically Hip Gong show this past summer! I was able to get my 4 GA tickets on the first try this morning. I used a single browser window, did not try hitting back or anything, just stayed patient while the search occurred. It took about 15-20 seconds per page to load.
Hope everyone gets their tickets! Good Luck