Resolution:
Accessing Dashboard or any page with a graph generates screen junk that looks like this

Locking assertion failure. Backtrace:
#0 /usr/lib/libxcb-xlib.so.0 [0xb12b0767]
#1 /usr/lib/libxcb-xlib.so.0(xcb_xlib_unlock+0x31) [0xb12b08b1]
#2 /usr/lib/libX11.so.6(_XReply+0xfd) [0x8668a1bd]
#3 /opt/jdk1.5.0_11/jre/lib/i386/xawt/libmawt.so [0x86810d3e]
#4 /opt/jdk1.5.0_11/jre/lib/i386/xawt/libmawt.so [0x867fad47]
#5 /opt/jdk1.5.0_11/jre/lib/i386/xawt/libmawt.so [0x867faec3]
#6 /opt/jdk1.5.0_11/jre/lib/i386/xawt/libmawt.so(Java_sun_awt_X11GraphicsEnvironment_initDisplay+0x26) [0x867fb106]
#7 [0xb1387028]
#8 [0xb1380b6b]
#9 [0xb1380b6b]
#10 [0xb137e234]

This is not a Federator bug, and it it is harmless. It appears to be an issue with Java apps and some non-Java apps on LInux (esp Ubuntu, maybe):

The fix described at the link below appears solve the issue for Federator:

http://bbs.archlinux.org/viewtopic.php?id=46798

also seen on Fedora too:

http://fedoraforum.org/forum/showthread.php?t=193746