The tabbed dialogs in recent build do not eraase background when switching tabs. This is regression introduced since November 20.
Timofeev, was it you? http://cgit.freedesktop.org/libreoffice/core/commit/vcl?id=a0a5eed63b871e2febb36e27e9dea4b7e57f681b
Yes, I am to blame, indeed... Thanks for the report.
Ivan Timofeev committed a patch related to this issue. It has been pushed to "master": http://cgit.freedesktop.org/libreoffice/core/commit/?id=59e59a16c1e9189458aafc9875eab989484f5191 fdo#57472: VclContainer: make it paint-transparent The patch should be included in the daily builds available at http://dev-builds.libreoffice.org/daily/ in the next 24-48 hours. More information about daily builds can be found at: http://wiki.documentfoundation.org/Testing_Daily_Builds Affected users are encouraged to test the fix and report feedback.
*** Bug 57499 has been marked as a duplicate of this bug. ***