Hi gpeters.. I asked around the shop today and got this for a answer..
"It is not advisable to put plywood over particle board. I would recommend removing the particle board as particle board is not suitable sub flooring. Regarding the gaps in the plywood, that should not create a problem. You should also install a vapor underlayment on the plywood before installing the hardwood."
"It is not advisable to put plywood over particle board. I would recommend removing the particle board as particle board is not suitable sub flooring. Regarding the gaps in the plywood, that should not create a problem. You should also install a vapor underlayment on the plywood before installing the hardwood."