Please see the most recent updates in the "Where did the .com name go?" thread. Posts number 16 and 17.
Yup, the .cab file is just a compressed archive much like a zip file but made using a different tool. It just makes the folder smaller to save disc space.On a side note, and you may already know this, but FS2004 panels work fine without having to create .cab files to contain gauge sets. You can simply place them in a normal folder structure and point them there, and all works well. I found this out after messing with cab file creators and not getting on very well!