USBCOM interrupt priority and debugging

Good afternoon. I'm facing a question about USBCOM (virtual serial over USB). My project has an interrupt driven data acquisition (with a message queue) and a USBCOM component to send the processed reads to the computer.

Everything works as expected but I have a doubt about interrupt priority. My 'input' PIN and all the USB interrupts have been assigned 7 as priority. Since my data is made of 'bursts' of packet, I thought that I should give my 'data capture' ISR a lower priority than USB (eg:6).

The queue should 'smooth' the peaks. What I find is that if I lower my ISR priority, USB seems to go wild, with the computer not responding to mouse anymore.

My ISR looks like this (DataReady is the interrupt pin):

CY_ISR(ByteArrivedISR)

{  

    EventRegister_InterruptDisable();

    DataReady_Disable();

... write input to queue

    DataReady_ClearPending();

    EventRegister_InterruptEnable();

    DataReady_Enable();

}

My main program writes to serial with a loop of

                 USBCOM_PutString(lineStr);

                while (0u == USBCOM_CDCIsReady());    

This is my first PSOC project and I must say that I'm impressed with the possibilities of the hardware and PSOC Creator (it REALLY rocks!!!).

More questions:

-is there a way to debug only 'main' program and not ISR ? Every step that I do moves to some interrupt handling routine for USB.

-is there some 'official' guideline to promote PSOC DIY opensource applications (logos/links to web hosting etc)