thanks david, appreciate it

I think I found a workaround if you want to trade max 2 pairs or more. The workaround is like this:
1. open all pairs that you want to trade with the same magic number
2. if you want additional pair, load the pairs again in a new window. This time use another magic number but must be the same for the other pairs.
3. This time you can trade with max 2 pairs at once, good luck