If they are attached inline all is definitely OK. But those that are attached but not inline, I think I've had problems with them myself. Let JayTBennett know.
I noticed this issue too. For instance, check out the post by Jimmy Cooper (02-28-2013, 02:08 PM, post #613) that contains an attachment, on this page: http://forums.windowscentral.com/windows-phone-8/201935-25.htm
In the WPCentral app, there is no option to view that attachment.