There are two types of CPU trap. One is from the health monitor which will be sent when the threshold is reached. Another one is the usage trap which will be sent whenever the CPU reached 100%, even if it is just a short spike.
The traps can be differentiated by the OID. The trap received from the health monitor MIB has the OID starts with .18.104.22.168.4.1.3422.214.171.124 in SGOS 5.x (defined in BLUECOAT-SG-HEALTHMONITOR-MIB.txt) and .126.96.36.199.4.1.34188.8.131.52 in SGOS 4.x (defined in system-resources.my). The trap received from the usage MIB has the OID starts with .184.108.40.206.4.1.34220.127.116.11 (defined in BLUECOAT-SG-USAGE-MIB.txt for SGOS 5.x and usage.my for SGOS 4.x).