keynote database error

We've started using keynote databases, mostly with good success. One glitch keeps coming up.

Sometimes when we Open a new drawing, Save the current drawing, or Reload an xref, we get the following error message: "Cannot Open Database <path> . . . .". We have to hit Escape several times (like a hundred times or so, could be equal to the number of keynotes maybe?) and it's annoying and time consuming.

It's an intermittent error -- sometimes it seems to crop up really bad, sometimes it seems to subside.

At times, we've been able to get around it by unloading and then reloading the database in Options \ AEC Content, but this last time even that's not working.

Help? . . . .