My CC (Masquerade, if it makes a difference) occasionally has tournaments with entry fees, along with a lot of free tourneys. I can enter and play in the free events without any issue (other than the damage incurred to my avg, LOL).
However when we have a tourney with a purse requiring entry fees, I can't enter, getting a message 'INELIGIBLE TO ENTER', or words to that effect. So what's up with this? In each case, I've had sufficient credits available to enter - just can't get in the door.