Moin, would have a question: how can you set the standard game mode on a server? (Hoste at "mchost24"). I wrote "adventure" in the properties of gamemode because you should be in the adventure mode. The / default game mode is also on Adventure, but you are always in the survival when you join the server!
You have to look at server.properties and then set "forcegamemode" to true
Look in the console, maybe you will see a configuration error there!
Ok, I'll give it a try.