DVD+RW Drive Freezes when Ripping Disc to Hard Drive

I can't copy DVD-R video 4.5GB discs. When I try to create an ISO on my hard drive from a Disc using Nero my PC Freezes. I can freeze at random times but usually after it's finished copying. I could try and copy 1 disc and it could freeze or it may let me copy several discs before it freezes. I have to restart my PC to get my PC working again. It's not just when creating ISO's. If I try to rip a DVD video from the disc using DVD Shrink my PC freezes. Also if I open the disc in Windows Explorer and then just copy and paste the files of the disc onto my hard drive - my PC freezes even though the disc is unencrypted.

The strange thing is - I do NOT get the freezing issue when ripping commercial DVD movies via DVD Shrink - only when ripping DVD-R movies which I've recorded from my TV. The only way I can copy a DVD-R is by using ImgBurn to create an ISO of the disc (which is strange since Nero freezes yet ImBurn does not). Then I can rip the files from the ISO using DVD Shrink.

I've have the latest firmware installed. I don't see anything with an exclamation mark in Device Manager and my PC is very stable apart from this freezing issue. I've even reinstalled Windows but I still get this problem. Please help.

My PC Specs:

Samsung DVD Drive SH-B083L.
Windows Vista 32 bit
AMD Athlon 64 X2 Dual Core 3800+ (2GHz)
256 MB Nvidia Geforce 8300 GS Turbocache (dedicated graphics card - not integrated)
4GB RAM (4 x 1GB) Samsung DDR2 800Mhz PC2-6400160GB