[Plugin: W3 Total Cache] How to cache minified pages?

Hi

First of all thanks for the excellent W3TC plugin.

I am using Google PageSpeed to optimize. PageSpeed tells me that the minified include files (see their URLs below) do not have expiration specified. These files are created by W3TC.

Is there a reason for this? Is there any way to specifically specify an expiration for these two files, without interfering with any other files?

http://www.porticor.com/wp-content/w3tc/min/b82dd9/default.include.1710310803.css (expiration not specified)

http://www.porticor.com/wp-content/w3tc/min/b82dd9/default.include.1952147925.js (expiration not specified)

Thanks!