toneAC and SD+Ethernet Shield pin conflict

Hi, I am having a problem with using toneAC along with the standard SD+Ethernet shield on an atmega 2560. I think the problem is a pin conflict on 11&12 which is used by both toneAC and the Arduino SD library. In an script, if I generate a tone using toneAC then I can no longer access the SD card in the same script without resetting the atmega… sd card works fine as long as I don't generate a tone. Does anyone have any ideas about how I could fix this? I took a look at the toneAC source but I don't know how to change the pins that it requires.. Yet I need to use both toneAC.h and SD.h.

Any suggestions would be greatly appreciated!

pinMode(SD_SELECT, OUTPUT);
digitalWrite(SD_SELECT, HIGH); // disable SD card
const char *filename = "test.txt";

Serial.begin(9600);

// Serial.println("Initializing SD Card...");
SPI.begin();
if (!SD.begin(SD_SELECT))
while (1)
Serial.println("SD.begin() failed");


Thank you!