CRC error when extracting v5.x-1.0-alpha2 tarball

I get the following errors while extracting the file:

"advanced_forum-5.x-1.0-alpha2.tar.gz: Cannot create advanced_forum\contrib\user_postcounts\user_postcounts.install"
"advanced_forum-5.x-1.0-alpha2.tar.gz: Cannot create advanced_forum\contrib\user_postcounts\user_postcounts.module"
"advanced_forum-5.x-1.0-alpha2.tar.gz. The file is corrupt"

I'm using WinRAR v3.20 on WinXP. I just confirmed I'm able to extract other tarballs.
Thank you for any help with this :)
Sc0tt