After the last update it changes zero to 1

Hey there,

So after one of the last updates the plugin doesn’t accept 0 (zero) as a price option for more than a couple of seconds, when it has everything configured to do so. I checked every single option and with a 0 or blank the bug it’s kinda weird:
– if I change the value to 0 typing it in, after a second or two it changes automatically to one but if I change it through the arrows (down to zero) it accepts the zero.

Can someone help me checking this? Because the site really lives for the free clients and they’re not that patient with workarounds ??

The page I need help with: [log in to see the link]