If at any point BOINC is neither computing nor transferring files, something is probably wrong; submit a bug report (see below).
Windows users: The BOINC core client (accessable via its system tray icon) has tabs that let you see projects, file transfers, work in progress, and messages. If you experience bugs, look at the file stderr.txt in the BOINC directory. If it's nonempty please include it in your bug report.
Unix and Mac OS/X users: This version of the client has no GUI, and writes to stderr and stdout. Please include any suspicious-looking text in your bug reports.
For news on BOINC, visit http://boinc.berkeley.edu
Please report bugs by sending email to the boinc-beta mailing list on SourceForge.net. To join this list, go to http://lists.sourceforge.net/lists/listinfo/boinc-beta.