The default Web Acceleration profile does not have any applications enabled by default so you are actually not routing traffic through WebAccelerator. Without knowing the exact error message it is very difficult to determine what is the problem with the profile.
My best guess is that the application defined in WebAccelerator is incorrect or missing. In the Web Accelerator application did you include the IP address and the domain name of the application? If a request is routed to WebAccelerator and the domain in the host header does not match any of the domains defined then the request will be rejected.
Nimbostratus