Incorrect working of Members table for Admin!

I have registered user who skips the payment and I want to add him a subscription plan manually (without payment). But when I open "All Members" menu, and click "Add" in the "Subscription" column for the same user, it displays the "Add member to a level" combobox where I may choose only "Visitor" or "Member". It is wrong, I asked to add a Subscription Plan, not a Level!!!