After installing the bunch of IDE-updates I got today the tooltip showing at mouse hover above a collapsed part of code contains only the line numbers (gutter) but no code.
I recognized it hovering a per default collapsed part of javadoc and could copy that behavior also at collapsed methods
Product Version = NetBeans IDE 6.9 (Build 201006101454)
Operating System = Windows 7 version 6.1 running on amd64
Java; VM; Vendor = 1.6.0_16
Runtime = Java HotSpot(TM) 64-Bit Server VM 14.2-b01
I can reproduce it for Ubuntu too as well at 6.9.1.
*** This bug has been marked as a duplicate of bug 189233 ***