iptables 1.4.19 in current openSUSE 13.1 makes funny output on rules with
non-CIDR netmask.

Example:

# iptables -N test_chain
# iptables -A test_chain -s 0.0.0.0/0.0.0.1 -j ACCEPT
# iptables -L test_chain
...
ACCEPT     all  --  0.0.0.1/-1           anywhere

A patch is available here:
http://git.netfilter.org/iptables/commit/?id=03e227017cca4f6d62a434bbaacf07e2869775b9

Maybe this could be considered for an update. Not critical, but given 13.1 will
have long term support (i.e. I plan to run it for a while) I thought I'd ask...