This is resolved in 10.2.1 and in the following patches for releases prior to 10.2.1:
10.2.0 - Spectrum_10.02.00.PTF_10.2.020*
(*This patch also includes a fix for SDM/SDC.)
10.1.2 - Spectrum_10.01.02.D101h
10.1.1 - Spectrum_10.01.01.D76j
The release notes show the following:
Symptom: Rare but consistent SpectroSERVER hangs due to multiple problems with the SNMP subsystem.
Symptoms can include failed online backups, failed shutdowns and invalid management agent lost alarms.
Resolution: Major overhaul of SNMP subsystem, designed to improve efficiency and stability.
If you need one of the PTF or D patches above, please open a case and request the patch (http://support.ca.com).