Is the server sending compressed response payloads? If so, LTM won't decompress it before applying the stream profile. You could check the responses using a browser plugin like HttpFox for Firefox or Fiddler2. If you want to prevent server response payload compression, you can use a simple iRule:
when HTTP_REQUEST {
HTTP:header remove "Accept-Encoding"
}
You could also use an iRule to configure the stream filter and only apply it to text responses. By default, when you use a stream profile and HTTP profile, both request and response payloads will have the stream filter applied. For examples of an iRule, you can check the STREAM::expression wiki page:
http://devcentral.f5.com/wiki/default.aspx/iRules/stream__expression
Aaron
Nimbostratus
