MA cross with negative period produce funny result?

[vnpython 0]

ok, was toying some ideas and using simple MA crossover without negative period (0) and the buy/sell works fine. and when i use -1 on 1 of the fast MA, it gives only sell trade. and when i use 0 for fast MA and -1 for slow MA, it gives only buy trade T_T are negative period gives such result?

[fxDreema]

Can you make some simple project for example, so I can see what are you doing, because I don't really understand what you want to explain here