Bug: Cookie expiry “infinity” does not work

Hello there,

we host several dozens of WordPresses with this plugin and have the problem that the setting of “Cookie expiry” to “infinity” just doesn’t work in at least Firefox, Opera, Chrome and IE11. If the setting is “infinity” the cookie generated is only valid for the current browser session. After reopening the browser and returning to the WordPress the cookie notice appears again.
If the setting is – let’s say – “1 year” the cookie is generated correctly and valid for the next year.

Please fix this bug as soon as possible.
Thank you very much in advance!