Very recently acquired an N9 64GB, which I'll freely admit I think is fabulous! only thing I can't seem to figure out is buying 'billboard' through the Ovi store.
Can search fine in the store, can go to purchase billboard fine, having previously added my credit card to my nokia account, but at the stage where I'm asked to confirm my nokia password, the screen renders but I get no keyboard with which to enter my password.
Really odd, as keyboard pops up just fine when using other applications, such as email, SMS, web browsing etc.

Help please!?

Sorry, may have put this in the wrong forum and it should possibly be moved to the Maemo6/Harmattan forum...

The sub-forum is fine IMO

When you get that screen can you minimize it by swiping it away and going to settings and checking that your keyboard is indeed installed and active?

yeah, keyboard working fine in other situations, just not when asked to confirm my nokia acc password at the point of having clicked the 'Buy' button after selecting an app to purchase.
The input field shows up fine, with cursor at start of the field, but keyboard won't appear, and I've tried activating Swype as my keyboard to see if that helped - it didn't.

ok, looks like I might be able to answer this one myself, more by luck than anything resembling judgement however.

Enabled Developer Mode on the handset, it rebooted, and guess what... works fine now, keyboard shows at the key stage of needing to enter my account password.

Not sure why this worked.

I don't remember as I've had Billboard installed since the very beginning; maybe it requires Developer Mode activated in its description?

Hence your problem was solved with the enabling of Developer Mode...