Optiplex 380 error 2 and 4 when connected to video switch

Hello at all,
when I connect the vga connector of my optiplex 380 to switch video (Belkin Pro 16 port) then I restart the pc it go on error 2 and 4 light. But if I connect directely my pc to video monitor all work well.
When I am connect to Belkin video switch and i do power off then i do power on with power button then all go well.
There is a problem when I connect with Belkin video switch and I do a restart (with power off all work well).

That is crazy and incredible...!

Thanks. Bob