root@t1000-tvp540-b:/var/tmp# uname -a
SunOS t1000-tvp540-b 5.11 11.2 sun4v sparc SUNW,Sun-Fire-T1000
root@t1000-tvp540-b:/etc/net-snmp/snmp# tail -3 snmpd.conf
proc httpd
proc sleep
root@t1000-tvp540-b:/etc/net-snmp/snmp# snmp\walk -v1 -c public localhost
prNames
UCD-SNMP-MIB::prNames.1 = STRING: httpd
UCD-SNMP-MIB::prNames.2 = STRING: sleep
root@t1000-tvp540-b:/var/tmp# pgrep -x sleep | wc -l
506
root@t1000-tvp540-b:/var/tmp# snmp\walk -v1 -c public localhost prCount
UCD-SNMP-MIB::prCount.1 = INTEGER: 0
UCD-SNMP-MIB::prCount.2 = INTEGER: 477
Your version, 5.4.1, is seriously outdated. Have you tried with a more recent release?
There has been a lot of fixes,also for the Solaris specific parts, so please try the current 5.7.3