SharePoint 2007-2010 content upgrade, Summary Links web part closed after upgrade.

Has anyone seen this before?

Did a DB content upgrade from SharePoint 2007 to 2010.  After the content upgrade (with only a warning saying that an unknown 3rd party web part was missing), we reviewed the new site, and found MANY pages which contained Summary Links web parts suddenly had many (but not ALL) of the Summary Links web parts now marked as closed.  At first we thought the parts were missing from the page, but when we edit the page we see the parts are in the Closed gallery.  We can add the part back in from the Closed gallery and all it's originally set properties are there.  Why are they coming up as Closed after the upgrade when they weren't Closed BEFORE the upgrade?

More details:

We have quite a few pages that contain one or more Summary Links web parts.  On SOME of the pages, one or more of these web parts are now Closed.  However, not ALL of the pages that contain these parts have the parts closed, and on the pages that now have these closed parts, not ALL of the Summary Links parts on that page are Closed, so it is not a problem with an unregistered Summary Links web part as the part is working on the same and other pages (I found other people on the web mentioning issues where NONE of their Summary Links parts are working after an upgrade.)  So, it seems to be somewhat random as to which instances of the parts are closed.  There is no information in the Upgrade Log indicating what happened.  The only error or warning in the log is talking about a different 3rd party web part that we know is missing in the upgrade as the company does not have a SharePoint 2010 version yet.  And that missing control is not even contained on any of the pages with the now Closed web parts.

So, here is what I would like to know:

1) WHY did SOME of the Summary Links web parts in our content DB get changed to Closed? (But not all)

2) How do we determine what Summary Links are now closed, so we can go and put them back without going to each page individually and editing them?  (Even though the properties persisted, having to replace the parts on the page will still be a pain.)

3) Why did the upgrade procces change the state of some of the Web Parts without so much as indicating it did so?

4) Has ANYONE else seen this before?  Anyone have a "Silver Bullet" idea on how to resolve this?

Thanks!

Paul