When you get the garbage, what happens if you hit "Shift-Reload"? Stays the same?
I noticed, that on some pages I'm getting "undefined class" (various JavaScripts) in the WebConsole. In my case, it does not affect the page rendering.
All, please tell me the thread numbers you've got the problem with.
One of them is 182 (pantyhose encasement)
(This post was last modified: 20 Oct 2015, 13:17 by Like Ra.)
Can you check the web-console? Tools -> Web-developer -> Web-console? Any errors, that are different from other threads? Usually you will see lots of errors, but some of them are serious (e.g. in red). Also, you can click on the "Network" tab in the web-console, check "All" at the bottom and "Shift-Reload" the page. Can you see where it chokes?
Did you try adding &ModPagespeed=Off at the end?
I've just discovered, that newreply.php?tid=182 gets ignored by Mod_PageSpeed! At least this is something VERY different!