Duplex or speed mismatch? What about VLAN trunking too? Can you check or reset the config on the new switch to factory defaults?
Hp Procurve Switches have auto mdix so no need of cross cables, they don’t even need trunk ports as they have different approach for VLANS, make sure you the cable is good, and also try to upgarde the latest IOS for the swicthes, configure speed and duplex setting for full and 100 or 1000. If you let me know to which ports you are connecting with the current configuration I can try to help you out.