After entering password to one protected node, node body is not visible on other protected nodes

I've run into an issue where after entering the password correctly for one protected node, if I go to other protected nodes with the same password, their body is not visible. I've traced it to protected_node_protected_node_hide() and the call in protected_node_node_view():

protected_node_invoke('protected_node_hide', $node);

Commenting this out seems to fix the problem. After entering the password once, a user can then see the full content of other password-protected nodes. Isn't this how it should work, or am I missing something? If this is how it should work, I can submit a patch. Thanks.