as to your problem i had met before, i suggest that you try this powerful iPod Transfer Pro ,this iPod Transfer Pro can copy files from iPod to your pc.
The supported formats include MP4, M4V, MP3, WMV, M4A, M4B, M4P.and so on.The "Search" function can help you to search your files in the categories of Genre, Artist, Album as soon as possible.you can download it from here
http://www.topsevenreviews.com/tipard-ipod-transfer-pro.html
The following instructions guides u:
Step 1: Download and run the Transfer
Step 2: Connect iPod to your computer, then the transfer can automatically load your iPhone into it.
Step 3: Click Audio or Video or all the contents of your iPod, and then music and videos will be automatically displayed
Step 4: Select the files you want to transfer by clicking the square icon.
Step 5: Click "Export to PC" button, then a pop-up window will appear for you to choose the place for the transferred files. After few seconds the transfer process will be finished.