Is my application causing cluster server crash?

I have a windows cluster with 2 servers running Windows Server 2003. Initially, my client-server application was crashing so I was fixing bugs with my code. Now, periodically one the two cluster servers will just restart itself (it's like a hard system crash to where the server just reboots).

The only thing I've noticed that looks a bit odd is that the memory that SQL Server 2000 (Enterprise Edition) uses climbs rapidly until it reaches about half the server's physical memory (~1.5 GB). According to the guy that setup the cluster, this is normal. I think that when a cluster server crashes, it is the one that is currently running the SQL Server.

My application uses ADO (VC++ 6.0) to access data in SQL Server (which is cluster aware). I've setup a program to simulate alot of network traffic (which means alot of database access; opening and closing connections the database constantly). When this stress test is run is when I notice SQL Server's memory climb constantly.

The server crash (restart) is random; think it has happened even without the stresss test going.

I'm desparate for any ideas or thoughts on this matter. Anyone ever experience something simular (i.e. a clustered server restarting itself)?