manually installing patches working but not showing up in patches repository

Dear community ,

I am trying to update my ESX1 5.1.0 build 799733 hosts with the list of patches below that I have freshly downloaded :

update-from-esxi5.1-5.1_update01

ESXi510-201305001

ESXi510-201210001

ESXi510-201212001

I have successfully installed my update manager plug in and I am able to manually import the zip files/patches within update manager .

When I am trying to create my baseline with the patches above , they are not showing up in the list and at the end of the manual import I have a message at the bottom of the window saying something like "0 content , 0 extension , 0 notification will be imported ....."

Any idea ?

ESXI version is 5.1.0 build 799733

Vcenter version is 5.1.0 880146

Update manager version is 5.0.0.8039

Thanks !!