what was session 548 doing?

[Taylor]

Adaptive Server Enterprise/12.5.3/EBF 12331 ESD#1/P/Sun_svr4/OS 5.8/
ase1253/1900/64-bit/FBO/Tue Jan 25 08:52:58 2005

I was monitoring a process today. And I found the executed statement
as below
1> select * from monSysStatement where SPID=548 order by StartTime
2> go
SPID KPID DBID ProcedureID PlanID BatchID
ContextID LineNumber CpuTime WaitTime MemUsageKB
PhysicalReads LogicalReads PagesModified PacketsSent
PacketsReceived NetworkPacketSize PlansAltered
StartTime EndTime
------ ----------- ----------- ----------- ----------- -----------
----------- ----------- ----------- ----------- -----------
------------- ------------ ------------- -----------
--------------- ----------------- ------------
-------------------------- --------------------------
548 912064712 5 0 0
12 2 1 114883 1253300 44
244566 21214063 0
200 0 512 0
Jun 14 2011 12:25AM Jun 14 2011 12:47AM
548 912064712 5 0 0
16 1 1 116646 1103300 44
211016 21273996 0
2814 0 512 0
Jun 14 2011 1:47AM Jun 14 2011 2:08AM
548 912064712 5 0 0
17 2 1 12693 21100 68
6136 323815 0
209 0 512 0
Jun 14 2011 2:08AM Jun 14 2011 2:08AM
548 912064712 5 0 0
18 2 1 7973 12500 68
2736 198452 0
213 0 512 0
Jun 14 2011 2:08AM Jun 14 2011 2:09AM
548 912064712 5 0 0
20 1 1 8733 20100 70
4448 262568 0
210 0 512 0
Jun 14 2011 2:09AM Jun 14 2011 2:09AM

It showed that from 12:47 to 1:47 there was no statement running. But
we had another job to capture sp_who output from time to time and I
found session 548 was in the output at 1:10 also 1:40(that's when we
run sp_who)
I am confused about this . Why it's not logged in the monSysStatement
during that time?
Can someone help to explain?