Hello, there: I had my project builded with 0 error as well as 0 warning. Then I tried to simulate it with dScope. When I push step by step to trace my flow, I found the flow will jump flying away to elsewhere, returning back after finishing some instruction. I downloaded it to my 8051, and it can't work. I tried to change optomize level, it will have some different result, but still the problem it's there were. Would someone please help me to solve this problem. Thanks a lot. Morris