PIC24F32KA304: Pull-up on RA4/CN0 not functional? (dirkjanb)

Hello, I cannot seem to get the weak pull-up of pin 34 / RA4 / CN0 to work using the following code:mPORTAInputConfig(IOPORT_BIT_4); CNPU1bits.CN0PUE = 1; The same code was confirmed to work for RB11/RB12. (CN15 / CN14). Thanks for any help...