Ok I lied. I got home last night jumped on my iPad2 and I too have the not formatted rich text error. I haven't updated that to the os5 software but plan to ASAP. I can still navigate and post but its a little buggy. So I downloaded opera mini for iPad to hive that a go, and that was worse! It doesn't acknowledge links correctly when you want to click a link it selects the entire page like you want to copy it!!! Drag!!!
Hm... Let me play around with it on my iPad this evening and see if I can offer you some suggestions. When running Opera Mini on my iPhone, I did have to zoom in a bit to make sure my finger was only touching the thing I wanted to click on (for example, the Submit button for posting). I'll see if that strategy is effective for the iPad, as well.
Another brower for the iPad you can try is called iCab. I haven't tested it yet with the new forum, but I have a feeling it's not a super-fast one due to all the "extras" it has available.