Server gamemode glitch?

[Jebussz]

So I've been running a Tekkit 1.1.5 server for awhile now and this "glitch" as i call it happend for only one friend of mine in which he is basically in creative mode ( by this i mean he can fly and his inventory looks just like a creative mode inventory ) but he can still take damage, which is funny when he dies from flying, and when you drops items into his item bar they disappear immediately.

I'm assuming something is just glitched and can be easily fixed because no one else on the server has this same issue and whenever i type /gamemode 0 for him everything fixes its self. The server properties are set for survival mode and I even have it forcing the gamemode as well. Also whenever he travels to a different dimension ( nether, end, mystage, pocketdim ) he re-enters his glitched state.

Now I don't know if this is a bug, and if it is i will gladly and immediately post this into the bug section. I just figured I messed up a setting somewhere somehow and maybe someone knows how to fix this.

[Karaktar]

Delete his player info on the server I can't quite recall atm how but it will fix the issue

[Jebussz]

Oh ok, I know how to do that. Thanks for the simple fix Karaktar. I'll delete his player info next time he is on so that i can make sure he doesn't loose his stuff.

[Inwoods]

I was about to start my own post on this, guess I'll just bump this. Apologies. I have exactly the same problem right down to the free flying and taking damage on landing.

Deleting my player info from the server did not solve the problem.

To add to the symptoms:

• You can delete blocks as quickly as creative mode but they are not 'gone;' you cannot walk through their space and they reappear when I relog.
  
• The problem recurs whenever I log in, or go to the nether or back. Changing worlds, basically. It also happens when I die.
  

I am running my server on fragnet, if that helps diagnose anything.

Edit: entering creative mode from this state also fixes the problem. So I have no idea what mode it is actually in. Seems to be neither creative nor survival.

2x edit combo: Yes I rebooted server, and deleted the player file while the server was offline. /world/players is the directory, correct? Is there another file that would need addressed?