So what you're saying is that it doesn't work properly in Firefox or IE and it's the browser's fault in both cases. I know this is just FOSS but that excuse doesn't fly in the real world.
In the real world, we have to code around differences with browsers so at the minimum, IE and FF are fully supported.
I"ve tested out your release for phpBB3 and those problems don't exist there, same browsers. If there are workarounds there, there are workarounds here as well.
I'll shutup now...