cfcache error

Hi and thanks in advance for reading this,

We are running CF6.1 on a Windows 2003 machine, and all has been going swimmingly for a couple of years. Our home page is pretty heavy, so we have been caching it using this code at the top of the template:

<cfcache action="cache" timespan="#CreateTimeSpan(1,0,0,0)#" port="80">

I recently noted that the home page seemed to be loading more slowly than usual, and I went to look at the logs. For the last 3 weeks, my application log has been filled with this new error:

"cfcache could not retrieve the page content. HTTP status code 'Connection Failure. Status code unavailable.'"

I can see the tmp file in the cache folder, and the folder hasn't moved, nor have any of the configuration settings (to my knowledge). When I blow away the tmp file, a new one is created as soon as I load the home page again. I can't find any trace of this particular error in these forums, or on Google. Please, anyone with an idea of where I should start looking for this problem - help!

Thanks again,
Molly