I have been racking my brain for months as to why the Dimensions (for 1.5, no legacy) template refuses to work properly when caching of any sort is turned on (i.e. eaccelerator, joomla cache, jre cache 3.1, etc). It all seems to be tied to the embedded IEPNGFIX (I even tried 2.02a).
While using the FF source view, I noticed no site URL's were showing in the code (only relative URL's were showing). So, after looking at the PHP used to grab the site URL in the Dimensions template (<?php echo $this->baseurl; ?> ) I wondered if this was a problem.
For Joomla 1.5 it is. The proper function to use for this is <?php echo JURI::base(); ?>. After I did a search/replace, the full site URL's were restored to the Dimnesions template. I haven't looked at other 1.5 templates but I thought I would share this.
This STILL didn't fix the transparent PNG problem for IE6 when caching is enabled!
<?php echo $this->baseurl; ?> is still correct syntax. You'll find in Joomla there are many many many ways to perform the same task. I've never personally had an issue with the baseurl function of Joomla. I don't know much into the roots of the Joomla API but it could be the syntax that worked for you is better for your server configuration but who knows.
Caching can cause lots of problems with various things in Joomla.
As far as the caching, the Dimensions template is the only one I have had trouble with. From what I can tell, I think the problem is with PNGFIX.htc and how it interacts with cached data but, it's the only one with PNGFIX having that problem. I tried a Templateplazza and YooTemplate and they seem to work OK.
Because it was a different PNGfix. The HTC file was removed and an image specific fix was included in the newer templates where only images with class="png" in their code would inherit the PNGfix. This causes less conflict.
After messing with this for weeks.. I think it's safe to say that Dimensions isn't cacheable with IE6. This is the only template driving me NUTZ with caching. Since there isn't an equivalent for IE6 like Firebug for Firefox, I can't think of a way to debug this and figure it out.
I have used the latest IEPNGFIX 2.02a, edited the template_ie6.php and hard coded the SRC just in case the embedded PHP wasn't picking up the dirname and nothing works...
STOP THE PRES.. I think I got it working with caching! I think the key here is a smarter caching product (I purchased JRE Cache 3.1 yesterday)... As a last shot, I turned off GZIP compression on the site (global settings) re-enabled JRE Cache and told it not to cache CSS and JS files and it seems to be holding.
If your running IE6, could you visit
www.web-jive.com
and let me know if it looks good to you and the speed is OK?