caching with class

Yes. Your error log will confirm this and your site will probably not work.

I've actually found that the best way to do this is to order your logic to where you "CACHE::disable" URI that shouldn't be cached and have a catchall. Be wary of "CACHE::enable" as it will override some of the cache directives in the profile. Look in the sample iRules for some idea's:

http://devcentral.f5.com/wiki/default.aspx/iRules/UsingIRulesToManipulateCache.html

I generally use the following format and it seems to work for our application:

 switch -glob [string tolower [HTTP::uri]] {
  "/uri1*" -
  "/uri2*" -
  "/uri3*" {
   CACHE::disable
   pool www.my.com_pool
  }
  default {
   pool www.my.com_pool
  }
 }