I'm also having this issue with several threads in the 3.5 forum, but not with others.
It happens both at home, and on my work desktop, so I don't think it's the PCs or browsers causing it.
The following threads/pages are currently problematic for me:
http://www.giantitp.com/forums/showt...-Threads/page7
http://www.giantitp.com/forums/showt...st-feats/page2
http://www.giantitp.com/forums/showt...t-Exist/page38