[Plugin: W3 Total Cache] Weird ? in cached pages

I am using W3-cache with regular page caching. I am hosting in rack space cloud sites.

SOme of my pages are getting weird charecters

Here is an example

Blogger to respond.? We have put all the requests in to Blogger to get the old site back, but they have not yet responded.? On a positiv

These pages look fine when they are not cached, does anyone have any ideas on why this might be happening.

thanks,

one more thing, just implemented MaxCDN, which really has worked well so far.