Page 1 of Goodmans GDVD122 stuttering sound on region 1

Just had my Dvd changed by Littlewoods Extra due to my previous Goodmans GDVD125 being unrepairable. My problem is when playing region 1 discs, there is a slight stutter in the sound. The strange thing is that there is a tv type button on the dvd remote control which switches the screen to either pal, ntsc or auto. When you switch it to NTSC the screen is in black and white and the sound is fine!! Any ideas at all?? Is it due to my Goodmans TV not picking the signal up correctly? I`ve never had any problems before with Region 1 discs on the same television. Region 2 DVD`s are fine. Please help as I don`t want to change the DVD as it came with surround sound speakers.

Sounds to me that the Goodmans is converting NTSC to PAL, 25 frames (NTSC) to 30 fames (PAL) per second, hence the stutter. When you switch to NTSC you are getting the raw signal. Your TV cannot handle NTSC that why the picture is black and white.