Dell 2407WFP Issues - Please HELP

Ok built system in 05. Have been running dual displays for 2yrs now. Got 24" and now issues. Ive hooked it up VGA, DVI and if I go into like Photoshop CS4 or even just sitting there after about 3 mins. The screen goes black, green lights are still there but it locks up. Running it at native res. I hooked it up s-video and component. The resolution sucked but it was temporary. Needed to get new cable. Had no issues then. So here is what I have:
Asus P5AD2-E-Premium
Intel i925XE
Intel Pentium 4 550 @ 3400 MHz
DDR2 667 3072 MB
RADEON X700 Series
Maxtor (204 GB)
Maxtor (123 GB)
WDC (200 GB)
External WD (500 GB)
SONY DVD RW DRU-835A
Optiarc DVD RW AD-7170S
E19T6W - 19 inches
MV88SE614x PCIe to SATA2 controller 88W8310 and 88W8000G Libertas 802.11g Chipset
MV88SE614x PCIe to SATA2 controller Yukon 88E8053 PCIe Gigabit Ethernet Controller (Copper)
MV88SE614x PCIe to SATA2 controller Yukon 88E8053 PCIe Gigabit Ethernet Controller (Copper)
XP Professional 5.01.2600 Service Pack 3
DirectX : Version 9.0c (December 2007)
PSU Antec Neo 650

I have ran a 17" and 19" off of the card for two years. No issues.

General Information :
Manufacturer : ATI Technologies
Model : RADEON X700 Series
Bus Type : PCI-Express
Texture Memory : 757 MB
Processor : ATI Radeon Graphics Processor (0x5E4B)
Converter : Internal DAC(400MHz)
Refresh Rate (min/max) : 56/75 Hz

GPU Information :
Number of GPU : 1
Processor : RV410
Memory Type : 256 MB GDDR3
GPU Frequency : 425.25 MHz - [initial : 425 MHz]
Memory Frequency GPU : 432 MHz - [initial : 432 MHz]
Texels : 3200 MTexels/s
DirectX Support : 9.0
Pixel Shader Version : 3.0

GPU Configuration :
Technology CrossFire : No

GPU Timings :
CAS Latency (tCL) : 4 clocks
RAS to CAS (tRCD) : 10 clocks
RAS Precharge (tRP) : 3 clocks
Cycle Time (tRAS) : 6 clocks

Video Bios Information :
Date : 08/26/04
ID : 113-A37904-101
Catalyst : 8.591.0.0

I have tested both cables on the other single monitor and it works. I can hook up S-Video or Component on the card to run both and they work. One VGA and one DVI is when it happens. Also when I hooked it up that way and booted for the first time and after. The 19" said "Range out of frequency" until it got to windows.