I was looking at my United FF account and saw the following on their web site:

"Star Alliance Upgrade Awards

Please note: We will no longer accept Star Alliance Upgrade Award requests at this time."

I'm a premier member and was planning on using my miles to upgrade when I go to Zambia, so I called them to see if this was correct and they told me it was. The star alliance is no longer accepting United miles for upgrades. United does have other partners who will accept their miles, but none that will get you to Africa from the US.

does this mean that the mileage accured on the SAA portion of the trips, when credited to the United ff program, are also not accepted by SAA?

Yup, that's what it means. Mileage is only credited to the airline plan you have. Star Alliance/Sky Team, whomever, does not credit mileage, individual airlines do. If you belong to United then you belong to United-- the Star alliance is a bennie, sometimes, as airlines do often coopperate.

Now, what the web site says is that United does not accept. We could be seeing a pissing match between the two companies. Call SAA in their US office and ask them if you can upgrade using the star alliance miles. It is possible the message means that United will not upgrade you if you carry the SAA card or other Star Alliance airline card.