gEDA-user: Cannot route pins from QFN

[David Carr <dc@xxxxxxxxx>]

Hi all,

I'm working on a board that uses a 28 pin QFN package.  Unfortunately,
whenever I try to route a trace away from the QFN part, the line that
I'm drawing just disappears.  I cannot route traces to the part from
other parts either.  If I try to run the autorouter on a obviously clear
ratwire I get a "No Path Found" error. 

To demonstrate this problem I've posted the file on my website:
http://oscar.dcarr.org/usb2lcd_rev0.pcb

The QFN part is the one with the paddle in the center of the board. 
Just try to route any of the ratwires to or from this part.  I cannot do so.

I checked the clearances for each pad and they are set to require 6mils
clearance (3mils per side) --- so I don't think that is the problem.

I'm using PCB 20050609.

Thanks for your help,
David Carr