Melon Bicycles 5005240 Slice Folding Bicycle

What happened

I locked my bike to a street sign with a Kryptonite combination U-Lock around 3:30pm. It was locked on the southwest side of Milwaukee ave, just north of the Logan Square outside the Logan Square 'L' station. When I returned to my bike around 9:30, it was gone, along with the U-lock. I distinctly remember turning the combination so that it was locked.

Bike details

Type
Folding / Compact Bike
Color
White
Size
compact, small tires, narrow, white frame
Condition
Gently used, some scratches. It may have a hair rubber band (brown) on the right handle that I used to hold my light on my bike. The seat pipe is worn to be adjusted for the height of a 5'2" woman.
Serial #
unknown

Theft circumstances

Date
Nov 13, 2012
Lock type
Other
Locked to
Locked to street sign.
How locked
Only the frame was locked a solid object.
How defeated
Lock is missing, along with the bike.
Duration
In front of the Kedzie Logan Square Blue Line Station for 3 1/2 hours
Area
Other situation, please describe below.