DMA Set problem

Hello, I don't know if the question have been already posted. I've SuSE 8.2 prof. installed in a PIV (Dell inspiron 5150) with a TOSHIBA MK4019GAX and when trying to set the DMA access I get: HDIO_SET_DMA failed: operation not permited. Which makes the system stop when accessing the HD. With the 'old' 8.1 version I do not have this problem. Can anybody help ? Thanks very much in advance. Celestino.