[Grease and dirt can hang up spokes where they cross]

Well, I think that that was it. tension seemed acceptable, no cracks, spokes looked clean but there was a small amount of dried dirt and grease on the points where the spokes crossed, cleaned that and Walla..
Still going to tighten them up 1/8 to 1/4 turn. it is an old wheel, about a 95 or so, and part of a set I use in poor conditions and to save the more expensive set.

I knew that someone would throw something obvious out that I was missing, such a smack the forehead thing to... thanks everyone