Ubuntu 10.x packages contains NetBeans 6.9 with wrong link to SwingX library. There is SwingX 0.9.2 in Ubuntu packages but NetBeans requires SwingX 0.9.5 only. It makes unusable DB tooling in NetBeans - issue 191325.
It is not easy to fix this in Ubuntu 10.x because of the Ubuntu release policies. The package libswingx-java should be updated to 0.9.5 first and then netbeans package can be fixed. But after Ubuntu is released it is prohibited to update to a new source version for the release, so it is better to fix this manually in your installation.
It is possible to fix this in dev version (currently "natty").
Anyway there is a workaround: you can download the bits of swingx-0.9.5 and put them into netbeans installation folder instead of the one version 0.9.2. So I suppose it is P2.
Will be fixed for 6.9 Ubuntu packages by publishing the swingx wrapper module as an update with increased spec version but identical content of the module, on Ubuntu specific 6.9 UC.
The patch for NB6.9 on Ubuntu will be instantly publish on UC , use Help|Check for Updates or wait a period for automatically checking for updates.
For download newer release NB7.0 and other use http://netbeans.org/downloads/index.html Thanks