Pass-through credits allowed per MAC address

[diver]

Hello fellows,
First of all Thanks for pfsense 2.0 very much

There is option at the page "Services:Captive portal" - Pass-through credits allowed per MAC address.
It seems it doesn't work.
My settings are:

Hard Time Out 40 min
Pass-through credits allowed per MAC address - 1
Waiting period to restore pass-through - 1 hour

user after successful authorization at the captive portal page surf web,
then after aprox 40min is user redirected to captive portal login page and
then still could do authorization, even with options mentioned above

Does anybody try this options?
Does anybody know is this just a declared options without any string of effective source code in project
or this is bug?

Thx in advance.