Problem Downloading Some FIles w/ iTunes

[robleeteach7418]

I'm downloading all the lessons and get the following error messages for several files. I'm not sure how to go about fixing this.

ERROR MESSAGE 1:
There was a problem downloading "xxxxx". A duplicate file name was specified.
Please check that the URL is correct and the connection to the network is active and try again.

ERROR MESSAGE 2:
There was a problem downloading "xxxxx".
The URL "http://media.libsyn.com/media/koreanclass101/......." could not be found on the server.

ERROR MESSAGE 3:
There was a problem downloading "xxxxx". An unknown error occurred (8006).
Please check that the URL is correct and the connection to the network is active and try again.

ERROR MESSAGE 4:
There was a problem downloading "xxxxx".
The network connection timed out.

[robleeteach7418]

So my iTunes has finished downloading what it could.

-The duplicate file name error fixed itself
-The time out error fixed itself

I still have problems with the could not be found on server error for the following files:
Beginner Lesson #1 - Self-Introductions - Audio
Beginner Lesson #1 - Self-Introductions - Lesson Notes
Beginner Lesson #1 - Self-Introductions - Dialog
News #16 - Video Homework - Audio
Audio Blog S3 #6 - What will You Talk About in Korean? - Review
News #71 - Time to Say Thank You, Thank You, Thank You! - News
Picture Video Vocab #14 - In a Classroom in Korea - Review
Extra Fun #4 - Advanced Lesson - Lesson Notes

And the 8006 error for:
Video #2 - How to Read and Write Hangul II (FREE!) - Hangul Video II (m4v)