Hi,
Sorry about that. This comes from the workaround used by VisualGDB to automatically resize List View columns. It tries to dynamically recompute the width of the Expression column based on the others, and it sometimes collides with the native WPF logic for resizing the columns.
Please try the latest VisualGDB 6.0 Beta 3. It defers the auto-resizing until you release the mouse button, so it should not interfere with the normal resizing and have this effect.