Re-boot of FSX necessary?

I did a few flights with various aircraft, then I started one with the DC-4 and I was only getting 7-11 FPS in internal and external views. I reloaded the flight and the same low FPS. I tried reloading my display settings with a 'current.cfg' still low FPS. So I closed FSX and reloaded the same exact flight, same weather etc with the DC-4 and have a steady 25 FPS internal and external views. Something had bogged down FSX. After rebooting FSX I thought to myself "that's more like it!" Has anyone else had this happen, and is there a quicker solution to restore FPS than closing and restarting?Thanks.