Help, I can't create servers anymore!

[Wolfy Snackrib]

I have this problem. When I create a server this happens to everyone that tries to connect:

Client dogma connected (84.183.203.1:27005).
Dropped dogma from server
Reason: This Steam account is being used in another location

Only a couple of days back everything worked fine but now I don't know what to do to make it work, help!

 

[VirusType2]

Did you install HL2 on another computer or do you think someone has assumed your identity? (stolen your account) It could be just a bug. I would want to talk to Steam Help if i were you

 

[Wolfy Snackrib]

Whoa whoa, I'm not dogma, dogma is some guy who tried to connect to my server. They automaticly get dropped :'(