Description of problem:
When I use dd command as
dd if=/dev/sdb1 of=/dev/null
(/dev/sdb is a 250GB USB HDD),
the data is transferred without problem till the transferred data reaches about 70GB,
but the command tried reading more data, the transfer speed is gradually decreased, and finally the process could not complete to read the whole data.
I tried the above command on other computer and other USB HDD with Fedora 16, but the result was same.
This command was succeed when I used recovery mode of Fedora 15's installation disk.

Version-Release number of selected component (if applicable):
kernel-3.1.6-1.fc16.x86_64

How reproducible:
Everytime.

Steps to Reproduce:
1. Attach USB harddrive.
2. Read big data (more than 70GB) such as the whole partition by dd command.
  
Actual results:
Whole partition cannot read from the disk because the transfer speed is gradually decreasing and become too slow.

Expected results:
Whole partition is completely readable by almost stable transfer speed.

Additional info:
Attaching result of lspci and lsusb of both two PCs.