I used
Replay AV and it actually worked

however I met some problems:
- The lectures are about 1:20 hour each and It took (Replay A/V ) about 6 hours to stream and download it.
- Many times the download stops before it complete the lecture (about 40 minutes) is there anyway to resume the download or even begin the download but after 40 minutes from the beginning of the stream.
thx in advanced