i can't block win98 computers

[vladone]

Problem solved.
I have two rules that refer at MAC.
1. allow arp traffic
2. block illegal mac
If i put first rule 1 and then rule 2 i can block only XP computers.
If inverse this order can block any computer.
If anyone can explain this :). But work in this mode.

P.S.
I can't put an rule to deny all because arp traffic. For this reason i
have an rule to allow this type of traffic.