Why did this order fail?

 
Why did this order fail? Why is SL or TP invalid here?

thanks

2006.06.15 08:14:51 '400313': order buy stop 1.00 GBPUSD opening at 1.8530 sl: 1.8500 tp: 0.0000 failed [Invalid S/L or T/P]
 
"MQL4: Execution errors"

see error 130
 
Thanks,

I will take a look.

Maji