Is Profile book not at all compatible with RC4?

I find I’m not able to install profile book 1.0 with RC4. It worked fine with RC3 and Joomla 1.5.8. Now when I try to install it, I get the following message..

File
/public_html/XXX/media/install_493e9df7bea6a/plug_cbprofilebook_1_0/cb.profilebook.php does not exist!

I was able to install other cb plugins and modules with no problem. I thought the install was taking place through the tmp directory, not through 'media' as this error msg suggests.

Would love to keep this component on the site. Any feedback would be appreciated.