Description of problem:
"vconfig add" does not work. It will give error on each interface.

Version-Release number of selected component (if applicable):
vconfig-1.8-7

How reproducible:
Always.

Steps to Reproduce:
1. Install FC4;
2. load 8021q module;
3. Run "vconfig add eth0 10";
  
Actual results:
"ERROR: trying to add VLAN #10 to IF -:eth0:- error: Invalid argument"

Expected results:
VLAN added without an issue.

Additional info:
In fact if to type in whatever string in place of IF then it will complain the
same thing.

The LAN cards are Tigon3 PCI-X 133 10/100/1000 and the box is HP Proliant DL380.