Help debugging a networking issue

[Roger Taranto]

I seem to have something configured on my FC2 machine that is blocking some
web sites, and I'm looking for pointers on how to figure it out.

Certain websites hang when I try to access them, and I believe it is because
packets are being blocked somehow.  However, I'm not sure what needs to be
unblocked.  In my /var/log/messages file, when I access one of these web sites,
I see lines like the following:
Sep 12 10:35:52 piper kernel: IN=eth0 OUT= MAC=00:a0:cc:74:17:a1:00:d0:79:28:4c:38:08:00 SRC=72.246.49.34 DST=198.144.206.7 LEN=60 TOS=0x00 PREC=0x00 TTL=58 ID=0 DF PROTO=TCP SPT=80 DPT=34385 WINDOW=5792 RES=0x00 ACK SYN URGP=0 
Sep 12 10:36:37 piper last message repeated 7 times

Can someone give me some debugging suggestions for this?  Is it an iptables
thing?  Is there a networking parameter that I've set wrong?

Thanks,
-Roger