Server connections

Hey guys, i have a bukkit server, its working fine and i have loads of pluggins. I can connect easily and my friend down the road can also, I've had a few others connect before but most people can't, the websites that check if a servers up say its offline and pmc cant find it. My friend tried to connect for ages and couldn't then he tried later on and got on. So why can some, but others not?

Bump

EDIT by Moderator: merged posts, please use the edit button instead of double posting.

 

Stable internet? Firewall?

 

What u mean

Go4Nightfire what do u mean

EDIT by Moderator: merged posts, please use the edit button instead of double posting.

 

If that wasnt the reasen then: Medic: I HAVE NO IDEA!

 

So it worked before, and now it doesn't?
Check to see if your ip changed,
then portforward again.