Quick Cache conflicting with s2member (Cache control headers

[james]

We use Quick Cache and have "Double caching" (client side caching) also enabled. Thus all no-cache headers were removed next we set our server's headers to:
Cache-Control : max-age=3600

Result: Works like magic on our server load!

Now the problem:

Today we installed s2member and its re-adding no cache headers . How can we stop this?

It adds:
Cache-Control : no-cache, must-revalidate, max-age=0
Pragma : no-cache

So header ends up looking like this:
Cache-Control : no-cache, must-revalidate, max-age=0,max-age=3600
Pragma : no-cache

As mentioned headers should only be:
Cache-Control : max-age=3600

It seems to only do this for guest on all the site posts pages etc.

Also, I disabled s2member temporarily and checked to confirm and once disabled the headers went back to:
Cache-Control : max-age=3600

How can I stop it from adding these no-cache headers?

thanks