Please forget all the package stuff in my last post they are not related
to your distribution I was confused by all those *studio distribution
sorry :)
Please refer to this HOWTO dedicated to your distribution :
https://help.ubuntu.com/community/UbuntuStudio/DapperPreparation
and specifically for your IRQ problem to
https://help.ubuntu.com/community/HowToVanillaKernelWithRealtimePreemption
You will have to compile the kernel yourself so unless you really need
extreme low latency I will suggest to keep your current kernel.
David C.