Problem with .GIF file and transparent

[markeddy]

I am inserting a .gif file onto my webpage (solid black logo with transparent background). When i first load the page, the image appears fine (nice crisp, black logo with the background transparent on dark red page). When i minimize the window and then go back to it, the .gif logo has gained a horrible white outline all the way round it which only disappears once i refresh the page.

Any ideas???????