File stunnel-4.15-2.el5.1.i386.rpm cannot be opened

The standard distro installation fails.

The beta distro installation fails.

Install gets to the point where file installation will begin (past stage2, disk format, etc), then an error dialog is displayed:

"File stunnel-4.15-2.el5.1.i386.rpm cannot be opened. This is due to a missing file, a corrupt package or corrupt media. Please verify your installation source.

If you exit, your system will be left in an inconsistent state that will likely require reinstallation.

[Reboot] [Retry]"

This is the first rpm to be installed, I think.

This is not a network issue, since the stage2 install image must be retrieved (via the internet) before the install gets this far.

The system is a virtual machine running under VirtualBox.

Update: PBXinaFlash’s net distro installs just fine, so this is net-distro related.