Description of problem:
On the Satellite v5.1.0 Activation Keys key screen, the "Usage" column does not show the number of Systems Registered Using This Key.  It only shows the "total" Usage limit set for each Activation Key created.  Tested on RHN 5.1.0 and compared to RHN 5.01.

How reproducible:
(1) Create Activation Key "1-T-A-AS-SN3AOI32"
(2) Set Usage to 1
(3) Save => Click Update Activation Key button
(4) View Activation Key on Activation Keys screen.  Usage shows only Usage limit of 1 and not 0/1.

Compared Satellite 5.1.0 to Satellite 5.0.1.  In Satellite 5.0.1 both the number of Systems Registered Using This Key and the total Usage limit set is visible => 0/1

Steps to Reproduce:
See above.

Actual results:
(1) create key "1-T-A-AS-SN3AOI32"
(2) Usage column shows only usage limit set "1"
Created Activation Key on Satellite v5.1.0 as follows:
Enabled?  Y
Description  T - AS - Applications Support
Key 1-T-N-AS-SN3AOI32
Usage 1

Expected results:
The Activation Keys screen => Usage column should show both the number of Systems Registered Using This Key and the usage limit set on the key => " 0/1".

Additional info:
RHN Satellite v5.1 .0 Reference Guide shows Activation Keys screen with Usage both fields.  The first number ( 0 ) preceding the slash is the number of systems currently registered and the second number ( 10 ) after the slash is the Usage limit set => 0/10