Messed up pricing - probably date field problem (VM 3.0.8)

[ExSpirit]

There's some strange problem at selecting date at prices if I use multiple prices. I added 5 prices and at the last price when I click on date field nothing happens (in console I am getting "n is undefined" and "Empty string passed to getElementById()." all the time). Also when I save settings are messed up (rules are usually changed to generic rules).

I am using Joomla: 3.4.1 and VirtueMart 3.0.8.