hmm, well you can't change the type or number of channels on the asio modules while cubase is open or you will get a freeze for sure.
are you using midi? if you have a controller connected, go to the "midi" menu in the routing window and put a midi monitor in the project. connect it to the pulsar midi source and tell me, are you seeing active sensing and midi clock messages?
you need to turn off active sensing on your controller. it is filling midi buffers and causing freezes. if you can't turn it off on the controller, you will need a midi filter. an external filter would be better, but there is a filter in scope that should work. it's in the midi menu where you found the midi monitor. connect it between the pulsar midi source and the sequencer midi dest.
also, be sure that in the bios, "plug and play os" is set to "no" if that setting is available and that "apic" is set to "disabled" if that setting is available.
active sensing seems to make troubles on some motherboards with xp and cwa for the reasons i mentioned(midi buffer overflow). it's a common problem. you needed to fix that irq problem as well.
