Multiple keyword search produces server disconnect

I've tested this locally (MAMP) and on live servers, and in four different Drupal implementations, and I keep running across this same issue, which was reported to us by a client a week ago.

Searching for multiple keywords in faceted search causes the browser to lose connection with Apache.

This happens only in these very specific circumstances:

• The search has more than one word
• "With all of the words" is selected (though this is default on some FS blocks)

I've tested this every way I know how; has anybody else run across this problem?