pixmap copying pixels from loaded to static

I have a function where I make a static pixmap and I am trying to make a function where I can change pixels in that from a loaded pixmap.

Function zgPixmapCreate:TPixmap( width, height )
	Local pmap:TPixmap = New TPixmap
	pmap.pixels = MemAlloc( width * height * 4 )
	pmap.width = width
	pmap.height = height
	pmap.pitch = width * 4
	pmap.format = 6
	pmap.capacity = -1
	Return pmap
End Function

Function zgCopyRect( source:TPixmap, target:TPixmap, x, y, width, height, tx, ty )
	For Local yy = 0 To height-1
		For Local xx = 0 To width-1
			Local src = source.pitch * ( yy + y ) + ( xx + x ) * 4
			Local des = target.pitch * ( yy + ty ) + ( xx + tx ) * 4
			target.pixels[des] = source.pixels[src]
			target.pixels[des+1] = source.pixels[src+1]
			target.pixels[des+2] = source.pixels[src+2]
			target.pixels[des+3] = source.pixels[src+3]
		Next
	Next
End Function

The above makes a pixmap which is set up using RGBA8888 format with 4 bytes per pixel. It works just fine when using two pixmaps that I have made with the first function, but when using a loaded pixmap as the source it copy over garbage pixel data.

I have tried to figure out how the format of the pixmap that gets loaded with loadpixmap command is set up. But even if I do a convert to RGBA8888 it doesn't work.

How would you copy pixels from a loaded pixmap to a static ?