Mandriva 2008.1: boot from USB hard drive

[Guest JimDandy]

Mandriva 2008.1 beta 2 recognizes my USB drive during install, and I can choose to partition, install, and install grub on that drive (/dev/sdb), but when I try to boot from the drive, I eventually hang with messages that there's no ext3 filesystem on /dev/sdb, even though there is. Has anyone successfully installed 2008.1 directly onto a USB hard drive and gotten it to boot? Thanks.