Really need some help here!!

I've a problem with the Date of birth dropdown addon.

It's been set up as instructed and everything looks ok.

But I realise it doesn't capture the date that was input by the customer. It ALWAYS reverts to 01 January year.

Even when I tried to edit it by logging into the account, it still reverts back to 01 January year.

Simply put, it doesn't capture and doesn't respond to changes.

What could be the problem? I've compared against the original files and I didn't spot anything. Could someone help please??

Here's a list of other addons i've added:
1) DOB dropdown
2) back in stock notification
3) column layout grid
4) login box (sidebox)
5) cc-accept (sidebox)
6) direct bank transfer
7) how did you hear about us
8) newsletter subscribe
9) simple removal of add to cart quantity box

My website: www.dermoglo.com/shop

thanks a bunch!