Hi all,
This is a bug in Qt 4.8.5, which is the version of Qt used in PI 1.8.0 RC7:
https://bugreports.qt-project.org/browse/QTBUG-34012Fortunately, this bug has been fixed a few days ago. We are very close to a 1.8.0 release version of PixInsight, so I ask for a bit of patience. Hopefully, the new version will be 100% compatible with Mavericks.
In the meanwhile, the workaround is using platform-independent file dialogs:
Edit > Global Preferences > File I/O Settings > Use native file dialogs (uncheck, then press F6 to apply globally).
Of course, PixInsight should not be added to Accessibility...
Sorry for the inconvenience.