Since we're talking about Virtual Library switching and we've eliminated most everything else, my suspicions have fallen on the VL search expressions, mine are simple. I guess there are performance implications if they're complex.
One way to test this would be to switch directly from a restricted VL to the All Books VL. For me that's Ctrl+Alt+Up-arrow. But that's a customised setting.
On Windows the default shortcut, Ctrl+Esc, doesn't work because Microsoft uses it to show the Start Menu. As an ardent user of keyboard shortcuts why anyone would use that sequence for anything other than 'Get me outta here… Now!' escapes me.
Maybe others know of search expression examples that could be used in a VL, which have performance implications. chaley?
BR