problem with payment for all users and sub sites

I am extremly concerned. The reason I chose marketpress as it allows all my customers to set up a online store with just a paypal email

but now I am getting this on the checkout and people are starting to mount up and moan at me

12203 – Instant payment required for 3pxo. – Instant Payment in 3PXO cannot be pending. The transaction has been rolled back.

similar problem here but I have no idea what the resolve was.

Also I noticed you now say only 10 sub sites can check out at once… is this all? also… where are the other global carts we used to have?