Pokemon Colosseum's U-Disk... WHERE IS IT?

Question

I have been picking my brain for five days! I can't find the thing! I've gotten to The Under (obviously) and defeated both Venus AND Ein. And yet, I still can't find the disk. Please help me!

Answer 1

Head into the Subway afterwards. Head into the Shadow Liner and exit.
Venus will taunt you that she has the only key to the Train, then run
away. Exit the station and right infront of the sign "Station" is a
glimmering object, which is the key. Now, go to the left side of the
train and use the key. After getting out of the train some Peons will
run off. Head up and get ready for a jolt. They explode the area near
you. Head inside the door, staring at the big hole they cut off the
access to the Shadow Pokemon Lab from your end. Go the right to find
the Main Gate Key, very important.

Head out the door and to the right, through the boxes is a chest with a
U-Disk. Use it on the UFO to get to a secret room with a Time Flute.

Answer 2

here... see my other answer to this question

here-> http://answers.yahoo.com/question/index;_ylt=Ak1xuq58iGIEQ4sXEbq9ICojzKIX?qid=20060904090618AATEh55