[horde] Problem with PNG Transparency (IE6)

[elziege7]

Hello!

I placed a Logo with some transparency in the upper left corner of the horde
workspace.
This works pretty well for all Browsers except the Internet Explorer 6 as it
has no support for transparent PNG.
The transparent area of the PNG is displayed as a white area.

Somenone suggested to use GIMP to save the image in indexed mode, but I
can't do this because the loss of quality is too high.

I found some older entries in the mailing list mentioning a fix for this
(e.g alphaImageLoader.php or alpha_filter.js), but I can't find any of these
files on my system.
I am using Horde 3.2.2 on a Debian Lenny System.

Can you please give me an advice?

Thanks in Advance!