Err... dweig. no. The Antec NEO HE 430W is capable of running two X1950PROs in Crossfire (but nobody does it). By no means it would be your PSU, the X1950PRO Ice Q Turbo AGP has many issues as many forum members pointed out. Some reason these HIS cards don't last very long and tend to have so many issues.
I repeat, the NEO HE is more than capable of powering 1 X1950PRO... one X1950PRO + Typical setup will only give you 300W of Power usage on average. Send the card back to HIS, also use the 7.6 Drivers - DO NOT whatsover install 7.7, 7.8,7.9,7.10, known instability issues have been already discussed.
(and don't bump ancient topics, and theres a clubhouse to discuss about the X1950PRO's problems, my sig).
AMD Radeon X1950~HD4000 Support Clubhouse
“Mac: "Woah, what are you doing?" Mac says as he levitates in the air.
PC: "Playing Half-Life 2, this is my gravity gun."
Mac: "Well I can sort of do that."
PC: "Technically Mac, you have to become me first."” -From_Nowhere