Unexpected behavior of Maple

I'm getting some strange behavior in Maple, and was hoping some of you could help me find out what's happening.

I type in this expression :

Now it seems quite straight forward that the roots of y(x) are i, -i, and 2.

Now when I ask Maple to find the roots for me:

I get this responce:

Maybe Maple can't handle 4-th order roots, fair enough. But the surprising part is when I make Maple calculate y(2) for me. The answer I get is:

How can that be?

I'm running Maple 11 btw.