File Dialog oddities in Mavericks

For some reason I can’t fathom, since upgrading to Mavericks, when I throw up a file selector dialog, it sometimes vanishes before I get the chance to select a file.

Has anyone else seen this behaviour?

In Xojo apps or in other apps? No, haven’t seen this. My file dialogs tend to show a spinning wheel for more than 10 seconds before they shows files. Drives me crazy.

I found a probable cause, for both our problems, I think.
The File Open dialog was defaulting to my Documents folder.
Which is well stocked.
One of the files was a vm of Windows 8
I moved all the files into tidy folders, and now the dialog doesn’t die.

With you reporting a spinning wheel, I think what is happening is OSX working hard to make thumbnails/icons for all the files.
Maybe a file the size of a VM is too much for it to handle.

Coverflow.
Found this:

Adobe