VB.NET Thread Pooling?

I created a Windows Service that uses thread pooling and works fine on a Windows 2000 Pro box. However, when the service is moved to a Windows 2000 Advanced Server the thread count exceeds the max threads for that process? Both boxes show that each process has a max of 25 threads. The average thread count for the Windows 2000 Pro box is about 6, where as the Advanced Server box hits the 25 threads fairly quickly with the same settings. What would cause this? Does it have to do with a difference in the way the two windows systems handle threading resources? Any comments or suggestions would be appreciated.