My Little MSI's Expansion Slots

[MoonPig]

Hey,

Just been messing around and i've noticed something odd. My board has 1x "PCI-E x1" and 6x "PCI-E x16". Now, i've just put my 5770 in different slots and this is the outcome:

PCI-E x16 Slot 1 - Works at x16 speed
PCI-E x16 Slot 2 - Works at x4 speed
PCI-E x16 Slot 3 - Un-tested
PCI-E x16 Slot 4 - Works at x16 speed
PCI-E x16 Slot 5 - Doesn't POST
PCI-E x16 Slot 6 - Too low to fit anything due to the case.

Now, two things. First, i had to re-install the drivers each time? That normal? Second, Why can't i POST in slot 5?

Thanks