> Extracting files using tape drive file:/backup/t2 on host hccweb.
> Load tape DailySet100 now
> Continue [?/Y/n/t]? y
> EOF, check amidxtaped.debug file on hccweb.
> amrecover: short block 0 bytes
> UNKNOWN file
> amrecover: Can't read file header
> extract_list - child returned non-zero status: 1

I just had this exact problem yesterday - in my case, I had to set 
amrecover_changer "changer" in amanda.conf, and then 'settape changer' 
at the amrecover prompt.  With that, it was able to load the tape by
itself.  Otherwise, I think you need to manually load/rewind the 
tape before trying to recover from it.  

That might not have anything to do with your problem, but I was getting
the same error message, and this fixed it.

Hope that helps,
Fran