Don the 2005 is not available because there was no camera in sw 2005. This pretty much made Maxwell useless with 05. With SW 2006 which will be a full release any day now, a camera was included by the SW developers. Maxwell uses the camera settings in 06 and works. I believe some people were using the 06 beta and getting renders out of maxwell this way.
I don't think next limit is going to add a camera support for 05. In short Maxwell Solidworks Plug-in only works on 06. If you plan on using sw 2005 you will have to export your scene to the Maxwell standalone, which will be out this fall.