Speed burning with Nero

I put a new DVD writer on this a PC, but when i tried to burn a film to a DVD it was taking over 12 hours, and in fact timed out. I teied Nero 7 which cut the time down to about 7 hours, but then would not play more than 10 minutes, however the film did copy but only played on fast speed on the DVD player.
So I'm back with Nero 6 which works fine on my other PC, never had a problem with it.
So i tried to burn the film to a folder, and it still took just as long.
I've checked the DMA that OK.
The Pc is old and runing Windows XP, and runs fine, really need help on this ASAP PLEASE