Ok, this worked for me and I've been f'n with this for days now. Try this!
1) Go to the program files directory where Knight Online is located.
2) Located Xpatch (You will see an icon)
3) Right click, go to Comptaibilty mode and check Windows 2000
4) If Windows 2000 doesn't work for you try all of them.
Like I said I don't know if this offical fix or not, but something I figured out while messing around.