The newly produced chipsets preserve compatibility with previous CPU, however, in case of Intel p35 express this is not true .
Test showed the presence of some problems with many models from the previous processors generation ( Pentium 4 LGA 775 ).
In particular, it was mentioned that some motherboard could not even load the operating system with the processor Pentium 4 560.
Let us recall, that this CPU has the highest clock frequencies among netBurst architecture processors and high thermal packet (115 W). At the current moment , the processor Pentium 4 560 was already removed from production, but in retail sale they still available .
Motherboard producers answered to the question about this incompatibility , AND they do not plan to modify the design of their products in order to ensure the support of those models.
So those who has old processor and plan to update their motherboard , check twice before making purchase.