[Gimp-user] Why GIMP adding white line to PNG?

[Keith Purtell <kpurtell imirus com>]

Today I converted a client logo to a Web png in GIMP. Simple blue text on a
transparent background. Although the GIMP original shows nothing but
"checkerboard" around the text, each time I exported a png, it ended up
with a white line across the top. After some tinkering, I stopped it from
doing that by making the canvas slightly taller. Possible reasons? (Tried
Google but find anyone else w/same prob.)

Keith