Weird frame rate drop!

As an update...I had two issues.1. An intermittent reduction in frame rate. 37-52, down to 23-27.2. A reduction in frame rate to one frame per second, once per flight.I've solved the first issue. It was caused by REX water. It occurred whenever i flew over a stretch of water. As soon as I reduced my water slider setting in FSX, frame rate shot up to 50-60 FPS.I know some are having issues with certain REX water textures, so it's a case of either reducing my water settings, choosing a different REX texture, or waiting for REX Essentials. Apparently REX have improved frame rate with water.As for the second issue, I found that when frame rate plummeted to one solitary frame per second, that if I panned up to the overhead the frame rate shot up to 50-60. Then if I pan back down to the main panel, my full frame rate was restored.A bit easier than switching to windowed mode and then back to full screen, but still a mystery all the same.