In reply to:
This would not be unusual if he had firewall software such as the XP personal firewall, BlackICE, ZoneAlarm, etc., running. Those would allow Hijack HTTP but not emplode. Again, covered in the ethernet troubleshooting tips here.
This is true. I forget about WinXP's built in firewall.
In reply to:
Also, I would think that if the player were on a different subnet than the PC, that HTTP would work but emplode would not. Also covered in the troubleshooting tips.
I'm virtually certain this wouldn't occur though. TCP/IP is TCP/IP - if you're connecting on port 21/80 or port 8300(?), it makes no difference - you can either get there, or you can't. The only case I could see this happening is if he only had the software scanning for the empeg, rather than having the IP entered. Even then though, I imagine the emplode software outputs a broadcast packet that would arrive and be replied to from anywhere.
Cheers,
A.