Thanks to fdiaz2day for the heads up in BPN
ATI Technologies' Director of PR, Chris Evenden, responded to accusations in cheating with the CATALYST drivers in order to achieve higher results in 3DMark03. The scandal broke on Friday, the 23rd of May, when Futuremark, the developer of the 3DMark03 issued a document stating that NVIDIA and ATI Technologies implemented cheats in drivers in an attempt to score better in 3DMark03 benchmark.
According to ATI's representative quoted by Beyond3D in their editorial over here, the 1.9% performance gain came from optimization of the two DirectX 9.0 shaders (water and sky) in Game Test 4. ATI rendered the scene exactly as intended by Futuremark, in full-precision floating point.
Their shaders were mathematically and functionally identical to Futuremark's and there were no visual artifacts; according to ATI Technologies, the company simply shuffled instructions to take advantage of their architecture. ATI states that these were exactly the sort of optimizations that work in games to improve frame rates without reducing image quality and as such, were a realistic approach to a benchmark intended to measure in-game performance.
However, ATI recognized that these can be used by some people to call into question the legitimacy of the benchmark results, and so they would remove them from their driver as soon as is physically possible. They expect them to be gone by the next release of CATALYST.
News source: XBit Labs