wmi ExecuteQuery fails with RPC server is unavailable error

[Deepthi]

Using win32 I am trying to get list of hotfixes that are installed in the
local system. I am using Win32_QuickFixEngineering to do this. The code gets
executed for every 5 secs periodically. It works properly in Windows 2000 and
XP. But I see a problem in Windows Vista.
After every 1hr I receive WBEM_E_SHUTDOWN error while executing
IWbemServices::ExecQuery or IEnumWbemClassObject::Next. Whenever I receive
this error I am releasing all the objects and calling
IWbemLocator:ConnectServer. Sometimes I am able to retrieve hotfixes with out
any error. But, sometimes I receive 0x800706ba (The RPC server is
unavailable) error during IWbemServices::ExecQuery or during
IEnumWbemClassObject::Next (Inconsistent).

Observations:
1. In Vista while executing this code a process "WbemPrvSE" process with
User Name "Network services" gets added in the task manager. As I am querying
for every 5secs handles and memory of the process is increasing. At some
point of time it is reaching a value higher than 4096 handles. During this
time the process is getting closed and restarted. In EventVwr I see
"WMI has stopped WMIPRVSE.exe because a quota reached a warning value.
Quota: HandleCount value:4169 Maximum value: 4096 WMIPRVSE: 2756".
Mostly during this I am getting shutdown error.

2. I used WbemTest.exe tool in vista just to verify if the memory and
handles get increased each time I make Win32_QuickFixEngineering query. I see
they get increased whenever I execute the query.

3. Also, form Command prompt I used WMIC tool to verify the same. When ever
I execute "qfe get hotfixid" i observe memory and handles of "WbemPrvSE.exe"
process increases.

Please kindly help me in resolving this problem.