Process memory increasing after switching user - wpf

Question

I've developed an app that runs on windows. It uses a 5 mintes timer to initiate a connection to an Web service and checks for any updates in a DataTable.
If there are any changes - it pops a WPF window on the client and shows a message.
The program runs in our domain using a Logon Script, and runs with the users account.
Lately we've noticed a problem, and found out that the process of the app was using over 2GB of ram on them, and increasing...
After looking it up, we figured out the problem:
The app runs on windows xp and windows 7 pcs. In windows 7, if a user uses the "Switch User" option, the process of the first user keeps on running, and the 5 minutes timer is still running. The memory leak strarts when there's a change, and a message should be displayed.
When we stopped the timer, and then used "Switch User" - There was no problem and the process stayed on a normal memory usage.
What can we do? Any suggestions?
Thanks!!

Answer 1

I use the following method to enumerate current users.
ManagementObjectSearcher searcher = new ManagementObjectSearcher("SELECT UserName FROM Win32_ComputerSystem");
ManagementObjectCollection collection = searcher.Get();
foreach (var user in collection.Cast<ManagementBaseObject>())
{
Console.WriteLine(user["UserName"]);
}
It might work in your app if you use this and compare with:
System.Security.Principal.WindowsIdentity.GetCurrent().Name
If not a match - pause the instance.
If you have a memory leak, it would suggest a missing dispose in your method too. I'd be surprised if you ended up with enough instances to merit 2GB memory allocation.
P.S - requires you add reference to System.Management