[OpenLayers-Dev] Are there png8 wms tile problems with IE?

[louvy.joseph at gmail.com]

I am cross posting this on both geoserver & openlayers lists..

Recently I was enquiring if any of you have seen the exception issues 
with geoserver 1.5.3. I have further problems with 1.5.3, this time with 
PNG8.

Is the png8 format rendered by geoserver-1.5.3 fully compliant with the 
PNG specs?  Please ignore my lack of knowledge on PNG. Are there any 
limitations or certain features not being implemented for this png8 
format? I am using Openalyers 2.4 on the client side. Everything is fine 
on firefox. But both IE6 & IE7 have problems with the  png8 produced by 
geoserver. This manifests in couple of ways:

1) Most of the times, the IE gets redirected to some other page when I 
use png8 format for openlayers wms layer. (If I use png instead of png8, 
everything is fine). I am hypothesizing that IE is not able to process 
the geoserver png8 and gets  confused.

2) Lot of times with png8, the openlayers lands in 
OpenLayers.Util.onImageLoadError() handler. Basically IE thinks that 
there is some problem with image URL; however the IE ends up drawing the 
WMS content of the png8 tile fine (but the tile soon gets replaced by a 
pink tile). Looks like IE thinks that there is something wrong with this 
tile even though it was able to render it fine. The problem does not 
consistently happen with one particular tile; the same tile on refresh 
comes out fine.

The support for png8 is very very important for IE6 since IE6 can't 
handle PNG24 transparency.

Any body has any ideas? Thanks in advance..
Louvy Joseph