Add To Cart Button Not Returning

We've been using a plugin for a while to hide out of stock variations but we are now looking at showing them. The problem i'm having is that if one variation is in stock and one is out of stock when the out of stock option is selected the Add to cart button disappears but does not return when the in-stock variable is then re-selected, any ideas?

Please share the URL of your website

http://www.jacksonsnurseries.co.uk/cupressocyparis-leylandii.html

http://www.jacksonsnurseries.co.uk/cupressocyparis-leylandii.html

Sorry, but looks like all variants in stock now

Sorry some one has updated the stock on that product

http://www.jacksonsnurseries.co.uk/thuja-occidentalis-smaragd.html

The 35 Ltr size is out of stock

I've solved the issue of the button not coming back, it was a line i'd modified to show 'Out of Stock' on rather than it just being blank.

Our customers are a bit stupid and ring up to say i can't add such and such to my cart!

I am glad to hear that the problem is solved.