You can logon to CSM and you see the products list but when i try to right click on a product release to 'Get Latest Maintenance', it doesnt work.
You get the regular windows options, ie copy, paste, etc.
Microsoft Internet Explorer
It's an MS IE issue..
Try to use another Internet Browser, Firefox or Chrome.
With Chrome it's working correct.
Or check the ZOOM rate of the window
If its different than 100%, make it 100% again.