I'm using gentoo-sources-2.6.16-r1
>>> Completed installing l7-filter-2.0 into /mnt/sandbox/portage/portage/l7-filter-2.0/image/
* checking 18 files for package collisions
existing file /usr/src/linux/net/ipv4/netfilter/ip_conntrack_core.c is not owned by this package
existing file /usr/src/linux/net/ipv4/netfilter/Makefile is not owned by this package
existing file /usr/src/linux/net/ipv4/netfilter/Kconfig is not owned by this package
existing file /usr/src/linux/net/ipv4/netfilter/ip_conntrack_standalone.c is not owned by this package
existing file /usr/src/linux/include/linux/netfilter_ipv4/ip_conntrack.h is not owned by this package
* spent 0.00394082069397 seconds checking for file collisions
* This package is blocked because it wants to overwrite
* files belonging to other packages (see messages above).
* If you have no clue what this is all about report it
* as a bug for this package on http://bugs.gentoo.org
package net-misc/l7-filter-2.0 NOT merged
marking CANTFIX due to limitations in the way the package is distributed (as a patch).
This may seem like a copeout but I realy can't see a solution here.
Please feel free to discuss this with me.