PT wood is definately paintable

[Moderator, Steve]

BUT, it will NOT stick regardless of primer IF the wood is still wet from all the chemicals. Normally, depending on your area, drying can take three months to one year.

If you paint PT wood when wet, the drying out of the wood will take off the paint with it.

Get a drill and with a small bit, drill a inconspicous hole and see if the saw dust is dry or still moist. If dry, go ahead, if moist and bunched up, wait.