dhclient and dhcp update require restart?

["Dariusz J. Garbowski" <thuforuk yahoo co uk>]

Hi, something that bothers me a bit... More and more system restart 
requests with each update (even if one doesn't use the package at the time).

Is this necessary for dhclient and dhcp update packages to require restart?
Wouldn't "service network restart" and "service dhcpd restart" in the 
install/upgrade
scripts do the trick (after checking that the service is actually running)?
Ssh used to do that since, well, as far as I remember.

Cheers,
Dariusz