Tekkit server problem - world never loads

[CameraFan]

I run a private Tekkit server, but whenever my friends try to join it the world never loads. The only plugins I have are Essentials and Lockette and NetherOres is disabled due to compatibility problems. Any ideas as to why this is happening? I can connect to it and play normally.

[Aelle]

My users have complained of this same problem, not to mention some ungodly lag since I installed tekkit. Not sure if the mods are to blame or if it's just something on my end-- because I'm hosting the server myself, I don't actually feel any of the lag.

[extant1]

Make sure your firewall/router allows 25565 for tcp and if not post the server log excerpt of them trying to connect.