I've never run into this one personally, but I did a Google search on "File descriptor 3 left open" and there were some promising looking hits (I did not pursue them however).
I don't know how to explain.
I have no problem to partition HD wiht LVM on GUI by running FC5-64/32 installers and Ubuntu-6.06amd64/i386/server-i386 installers. But I failed to run command lines to partition HD with LVM on running Ubuntu-6.06amd64/i386/server-i386 installers. I have a limited movement in running the latter installers because only base packages downloaded, many commands not available, even "less". Neither can I move the screen backwards with [Shift]+[PageUp/Down].
I shall make my last retort running FC5_32 installer. I also googled around but can't find a solution.