tcp sequence no. query

Hi all,
I am anyalysing tcp sequence no.s on single pc by running TCP socket
program on ethernet card with ip 192.168.1.200. For that i added debug
messages in tcp_v4_rcv and also in tcp_transmit_skb to check what seq.
no. are used by kenrel 2.4.24. What results i found by doing dmesg on
console is that

-----------OUTPUT INTERFACE FOR TCP PACKET CONNECT----------
TCP_CONNECT
After push tcp header in tcp_transmit_skb th->seq=-745717026
After push tcp header in tcp_transmit_skb th->ack_seq=0
After pull tcp header in tcp_v4_rcv th->seq=-745717026
After pull tcp header in tcp_v4_rcv th->ack_seq=0

But that is happening once in 10 times. Why am i got above -ve seq.no. results?
regards,
linux.lover