Rename your volume group. You've got a name collision going on.
/dev/root is normally a symlink to the partition holding your / filesystem.
LVM uses /dev/<vgname>/<lvname> so if you make the mistake of naming your volumegroup 'root' or anything else that matches any other existing device in /dev then you're going to run into problems.
I suggest you pick a standard prefix or suffix to give all your volume groups and lv names
rootvg/lvroot
rootvg/lvusr
rootvg/lvtmp
bkupvg/lvbkup
...etc is the scheme I use.
I use 'rootvg' and not 'vgroot' because I'm used to seeing it this way around on AIX, though keeping it consistent by just using a prefix rather than prefix/suffix (so vgroot/lvroot) probably makes more sense if you're not already used to seeing it a certain way.
Don't forget to alter your fstab, lilo and initrd if you rename your vg/lvs.
Still, at least you had the sense to name them rather than to leave it as volgroup00/logvol00 like many people do! Which drives me nuts!!
Hope that helps.