When a client runs into problems doing data imports, running queries and other activities, you can use the log files to find help track down what caused the problem.  To find the logs from the front end, you can search in the Schedule Administration Screen.  This screen shows both scheduled and ad hoc jobs are listed here.  By clicking on the search button, you can narrow your search for specific jobs that ran.  Note that the log may contain multiple pages, and if there is an error it is usually toward the bottom of the last page.