Help!!! Strange reading problem.

I am using a Mercury 8x DVD Burner to back-up games and movies, however, i have always had slow read/write speeds and it wasn't until i visited these forums that i realised they were slow.

I have been reading through all of your threads, and have fixed my slow writing speeds using the DMA/IDE method, however, the reading speed is still giving me problems. When using Nero the reading speed continually changes, going from 12000KB/s, to 1000KB/s and back again in an instant. When I have set it to only read at 4x speed.

Using DVD Decrypter i set the read speed to 4x and i get this:

I 18:48:49 Source Device: [1:1:0] DVDRW IDE1008 0159 (D (ATA)
I 18:48:49 Source Media Type: DVD-ROM
I 18:48:49 Source Media Region Code: 1, 2, 3, 4, 5, 6, 7, 8
I 18:48:49 Source Copyright Protection System Type: None
I 18:48:49 Destination File: C:\Documents and Settings\Edwards.EDWARD\Desktop\tempgame\PRIMAL.ISO
I 18:48:49 File Splitting: Auto
I 18:48:49 Read Speed: 4x
I 18:48:49 Detect Mastering Errors: No
I 18:48:49 Remove Macrovision Protection: Yes
W 18:48:49 [1:1:0] DVDRW IDE1008 0159 (D (ATA) - Selected Read Speed: 5,540 KB/s (4x)
W 18:48:49 [1:1:0] DVDRW IDE1008 0159 (D (ATA) - Actual Read Speed: 4,155 KB/s (3x)
I 18:48:50 Extracting Sectors... (LBA: 0 - 2237471)

When i set the read speed to 2x i get

I 18:50:03 Source Device: [1:1:0] DVDRW IDE1008 0159 (D (ATA)
I 18:50:03 Source Media Type: DVD-ROM
I 18:50:03 Source Media Region Code: 1, 2, 3, 4, 5, 6, 7, 8
I 18:50:03 Source Copyright Protection System Type: None
I 18:50:03 Destination File: C:\Documents and Settings\Edwards.EDWARD\Desktop\tempgame\PRIMAL.ISO
I 18:50:03 File Splitting: Auto
I 18:50:03 Read Speed: 2x
I 18:50:03 Detect Mastering Errors: No
I 18:50:03 Remove Macrovision Protection: Yes
W 18:50:03 [1:1:0] DVDRW IDE1008 0159 (D (ATA) - Selected Read Speed: 2,770 KB/s (2x)
W 18:50:03 [1:1:0] DVDRW IDE1008 0159 (D (ATA) - Actual Read Speed: 6,925 KB/s (5x)
I 18:50:03 Extracting Sectors... (LBA: 0 - 2237471)
I 18:50:06 Abort Request Acknowledged

The Actual read speed changes everytime i run this, sometimes saying 12x speed.
However, every time the speed starts at about 1x, and finishes at about 5x.
I have tried about 7 different types of discs, but still no help. My cousin is using the exact same disc, and burner, however, on an older computer and all of the read and write speeds are correct.

When i use DVD shrink the read speeds are extremely slow. When Nero burns at the random speeds all i end up producing is a coaster. Could someone please help me out, i would be extremely greatful.