They replied to me today saying that they couldn't reactivate my YPN account but encouraged me to join the program when it exits beta. Go figure.
I might be wrong, but I read this as:
- YPN has no smartpricing at the moment. - Sites like yours (I assum they have a high eCPM but low conversions) are not profitable for the advertisers - So, you are now blocked, but when YPN will exit Beta (i.e., have something similar to smartpricing) you can get back in, as your clicks will be discounted.