I pressed the descend button on Diamond Titan Gate to T3. The Gate descend locked up (I have 2k cr and about 2k ce). I exit SK and relog. I log back in to find an outstanding -19540 cr! http://i213.photobucket.com/albums/cc5/OSVG/spiral_2011-05-18_23-30-31.png.
I cannot descend into even T1 (via terminal) now.

EDIT: I tried join a T1 party (depth 0) and I zoned in and returned to 0 crowns. I can now access 0 cr cost depths.