Firefox 3.6.17 v IE9.beta

Hi there I wonder if any of you could point in me in the right direction. I have set up a PunBB Forum and embedded it inside my own #wrapper, within my website by modifying the main template  file, this displays beautifully in Firefox, however in IE9 it is a right mess.

The problem in IE9 is this. If we use the main forum root page for  example. All my website displays fine. and the majority of the PunBB sits inside the #wrapper as coded to, including the catagory titles and the footer section ofthe PunBB... It is the Forums themselves that are taking up almost double the width of the wrapper and throwing everything out.

can somone tell me which CSS element controls the size of forum TOPIC field if you will.... or even better, give me the solution to this problem...

No links as yet, as ths project is running form LocalHost, but I could paste code if  required.

many thanks