animating more than one character

Hello guys,

Am trying to animate two characters using a single blend file. The first character has a running cycle i used the offset bone feature in the NLA. it works well but the problem is that when i create and NLA strip for the running cycle of the second character, it takes the NLA strip settings of the first. Please what could be causing it?? or is it normal?? If its normal how then do i animate two characters walking or running on same scene??