You were quite right about the F11 netinst.iso - I began custom partitioning and had two problems: only 5 of my 8 existing partitions were found and identified, and when I attempted to delete the LVM nonsense (I have no LVM) I was warned that all data on all partitions would be lost.
So, I backed up to the select language screen and rebooted - fortunately no damage was done to my existing installations. Apparently I did not reach the point where the partitioner begins messing with the drives, but I have the feeling I came pretty close. Without your warning (http://forums.fedoraforum.org/showpo...09&postcount=8
) I might well have gotten into trouble - thanks again.