ripples crashed with SIGSEGV in gettimeofday()

Binary package hint: xscreensaver

i just used the lock screen applet of gnome panel.
when i logged in, there was this ripples crash report waiting for me

ProblemType: Crash
Architecture: amd64
Date: Thu Feb 28 22:58:14 2008
DistroRelease: Ubuntu 8.04
ExecutablePath: /usr/lib/xscreensaver/ripples
NonfreeKernelModules: nvidia
Package: xscreensaver-data 5.04-2hostname2
PackageArchitecture: amd64
ProcCmdline: ripples -root
ProcEnviron:
 PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/lib/gnome-screensaver/gnome-screensaver:/usr/lib/xscreensaver:/usr/lib/xscreensaver
 LANG=en_US.UTF-8
Signal: 11
SourcePackage: xscreensaver
StacktraceTop:
 gettimeofday () from /lib/libc.so.6
 ?? ()
 __libc_start_main () from /lib/libc.so.6
 ?? ()
 ?? ()
Title: ripples crashed with SIGSEGV in gettimeofday()
Uname: Linux 2.6.24-10-generic x86_64
UserGroups: adm admin audio cdrom dialout dip floppy lpadmin plugdev vboxusers video