Deferring delivery because other requests are in front

What does this message mean in the cache.log on squid 1.2b7?

97/12/02 19:35:02| clientSendMoreData: Deferring delivery of
97/12/02 19:35:02| --> http://retsik-software.com/a32_50.exe
97/12/02 19:35:02| --> because other requests are in front

Is this because the client just has too many requests going, or is there
some value I need to pump up?

Evan
Received on Tue Dec 02 1997 - 16:41:59 MST