Getting "The application has encountered a problem. We are sorry for the inconvenience" and "[Sa (4242561)

Almost every time the schema browser is open (Vista machine), this error occurs. The initial display is fine, then click once to select a table and a dialog box appears, "The application has encountered a problem. We are sorry for the inconvenience."

After clicking OK, another prompt appears, "[SafeCall Exception]: The system can't find the path specified" (or Access denied). Occasionally, but rarely, the schema browser performs as normal. Sometime normal work can continue after these errors. More often, Toad needs to be restarted.