I took 100 X 100 off the map this afternoon. I can go some smaller, however, a lot of my customers are older and do not see as well as they once did. Sometime, I just have to split the difference. I have talked to several firefox users that said it looked fine. I will keep my ears open on that one. Ken Sweet
You need to take a closer look at your HTML source code, much of it appears to be invalid which could be causing unanticipated problems in various browsers/versions. In addition, the IMG tag that points to your map image doesn't appear to be closed properly, which can definitely cause problems. Also, the use of tables for web design used to be the norm, but today people use divs styled with CSS for greater speed and flexibility, something you might consider doing.
Lastly, it's worth noting that many people such as myself block all scripts so it's a good idea to try and not be overly dependant on it for critical areas of your website.