Awful differences between browsers

I recently installed wordpress for a site I’m planning, at http://elfintechnologies.com. One thing I’d hoped for is that by using wordpress, some of the old hassles with pages looking grossly different on different browsers would be gone. Looks like that isn’t the case at all! I primarily use Firefox myself, but of course always check web pages I make in other browsers I happen to have. I chose the Displace themm because I likes the dark green background, and liked the way my LONG site title (Elfin Technologies) fit in the left sidebar. Well now I look at my static page on IE 8, and was pretty disappointed. Not only was the color of the left sidebar completely gone and replaced by GRAY, but the site name gets cut off to read “Elfin Technolog”, because the font is way too HUGE. Then I went and looked at the site using Chrome, and now there isn’t even a sidebar… instead the site title bar is in a horizontal section on top.

O’m no super HTML coder, but I’ve done my share of sites by hand, and I certainly could have done a much better job making a page look a whole LOT more similar in format without a lot of trouble. Can anyone shed some light whats going wrong here? Have I just chosen a horrendously poorly tested theme?