When you (Go Advance) it brings up another page. You scroll down to add attachments and click the link to bring up the little window with to Browse with. Well that little link is absent on my screen.
I never use the quick reply feature, I always use the "Post Reply" button. But just to be sure, I clicked the "Go Advanced" button in the quick reply area, and had the attachment button showing.
Sooo...I think VB might be onto something here
Sorry man, don't know what else it could be...maybe try the Post Reply button and see if it's available that way?