First I would like to apologize for my bad english.
I've got a strange situation...
I'm using 2 PCs with 3 monitors... this is the normal part

The layout is the strange part,
The 3 monitors / 2 PCs are configured like:
[PC1-Mon1] [PC2-Mon1] [PC1-Mon2]
In display settings of PC1, I configured Monitor2(Mon2) to the left of Monitor1(Mon1)
In multiplicity, PC1 is left of PC2 (the one with the mouse and keyboard)
So, what I got is...
When I go left of PC2, I control PC1...
Going farther I'm in PC1-Mon2...
But if I go farther, I don't go back to PC2...
Is there something I would configure so I can do that?
For now I'm using synergy...
In synergy I configured: PC1 left of PC2, PC2 left of PC1, PC1 right of PC2, PC2 right of PC1, so it doesn't matter where my mouse goes, it will ever find a computer...