What is going on in the db log - V6.1

Yahoo Archive
1
can anyone tell me why there are so many logout/login entries as recorded below?
these entries occur when a user is already logged onto vantage. Is there any entry
every time a user goes to a different screen?

10:11:44 SRV 12: Logout usernum 117, userid , on HACKMANDPCNEW. (739)
10:11:44 SRV 9: Login usernum 117, userid HackmanD, on HACKMANDPCNEW. (742)
10:12:05 SRV 9: Logout usernum 117, userid , on HACKMANDPCNEW. (739)
10:12:06 SRV 9: Login usernum 117, userid HackmanD, on HACKMANDPCNEW. (742)
10:12:29 SRV 9: Logout usernum 117, userid , on HACKMANDPCNEW. (739)
10:12:30 SRV 9: Login usernum 117, userid HackmanD, on HACKMANDPCNEW. (742)