[expert] Disk Swapping

[hamkas]

folks,
    i've got this weird problem where my system starts to swap heavily after one
or two weeks of continous running.  The only thing i have running is squid and
tkined.  Once it starts swapping i have to reboot the system as I can't kill the
x-server with cntrl-alt-backspace.
    Can this be caused by squid itself?