Software Update Server MCX settings confusion

Getting my head around SUS have been easy so far, there really isn't much to it. But I am now confused. Two machine groups in OD. Group one points to SUS server one Group two points to SUS server two or so you would think. But... my Mac in group two refuses to listen to server two, unless I disable the pref setting in group one. This I do not understand. Also (while i'm here) Even though I have a PPC Mac with 10.4.6 on it, it does not see the 10.4.7 upgrade as being 'available' to it, even though it is enabled on my SUS. The list of updates on the SUS, start out with nice meaningful names, but then start to list the build? number / dir / of the patch with a 061-xxxx number. While I understand that they are updates, I'm slightly confused why we need to see both and wonder why I'm seeing these at all. TIA. mg.