This is likely a regression caused by the fix of issue #186672.
Since the fix of issue #186672 will be ported to 6.9.1, this needs to be as well.
Fixed in changeset: 173080:a4b8f13ca1da
Integrated into 'main-golden', will be available in build *201006170001* on http://bits.netbeans.org/dev/nightly/ (upload may still be in progress)
Log: #187654 Assure that the columns are matched.
main #a4b8f13ca1da transplanted to release691 #73f47f81d8a3
Verified in NetBeans IDE 6.9.1 Dev (Build 201007152301)