SL 55 AMG, power loss

Hello everyone, for two years I have been “stolzer owner” of an SL 55 AMG (model 2003). For some time now the following problem has been resolved: With fast motorway ride about 240 – 250 km/h (vehicle has vmax 300 km/h) with brakes at approx. 200 km/h “misses” at the subsequent acceleration about 1/3 of the power. Even at full speed it takes considerably from 210 km/h to 220 km/h to accelerate. Who drives a SL 55, knows how fast this usually goes. The power is back again. Does anyone have an idea? Is this perhaps an electronic problem? Bernd