Stock opening balance

[mongolie2006-gnu at yahoo.fr]

Hello.

I have GNU Cash 2.2.9. I opened a new file, choosing "Investment accounts", and unchecking "Common Accounts". But in this case there is not even an "Equity" account. So I added later "Common Accounts" by New → Account hierarchy.
Nevertheless, when I create a new Stock account, as soon as I have selected "Account type: Stock", the thumbnail "Opening Balance" of the "New account" window is not modifiable any more. And if I set it before choosing "Account type: Stock", then it's reset to 0 as soon as I select "Account type: Stock". I also tried to add an account of type "stock" inside "Equity", but it's not possible. All accounts there have to be of type "Equity", and the Security/currency field of their "New Account" window can only include a currency, not a security.
  So, how to enter the initial numbers of my shares (stocks), the numbers given by my bank for the 2009-12-31?