Servo Library Error for Mega32

Hi,
I'm a newbie in Arduino and esperately need help in controlling servo.

I used Mega32 and when i want to compile 'sweep' example, it returns error and said that variable TIMSK1 and TIFR1 is not declared. Butwhen i switch the board to other board, it works and successfully compiled. What happen? Is servo lib is incompatible with Mega32 board? Does it mean that i need to use other board that Mega32?