That's good news, thanks.

I worked around this by using a different name for the category and the
service.  This is fine for now.

Now I'm hitting another problem.  After I Delete the category and re-Create
it, I then add the new counters using code as follows:

                // Remove any hanging or previously-created category information
                if (PerformanceCounterCategory.Exists( _perfMonCategoryName ))
                {
                    PerformanceCounterCategory.Delete( _perfMonCategoryName );
                }

                if (_perfMonCategory != null)
                {
                    ApplicationLog.Log( LogType.INFO, 0,
                                        "PerfMon Statistics are being replaced for " +
                                        _perfMonCategoryName);

                    foreach (PerformanceCounter pc in _perfMonData)
                    {
                        pc.Close();
                    }
                    PerformanceCounter.CloseSharedResources();

                    _perfMonData.Clear();
                }

                // Register the current process with PerfMon as a new category of
counters, with
                // one entry in a list of counters per Statistic for the process
                CounterCreationDataCollection newCounters = new
CounterCreationDataCollection();
   
                foreach (Statistic st in _statistics)
                {
                    CounterCreationData newCounter = new CounterCreationData(st.PerfMonName,
                                                                            st.PerfMonName,
                                                                            PerformanceCounterType.NumberOfItems32 );
                    newCounters.Add(newCounter);
                }
   
                _perfMonCategory = PerformanceCounterCategory.Create(
_perfMonCategoryName,
                                                                     ColorPaletteHelpString,
                                                                     newCounters);

                // Export the initial values for each counter
                foreach (Statistic st in _statistics)
                {
                    PerformanceCounter newData = new PerformanceCounter(
_perfMonCategoryName,
                                                                        st.Name,
                                                                        false );    // writable
                    ApplicationLog.Log( LogType.INFO, 0,
                        "PerfMon counter:" +
                        newData.CounterType + " " + newData.CounterHelp);

                    newData.RawValue = st.iValue;
                    st.Counter = newData;

                    _perfMonData.Add( newData );
                }
            }

In the debugger, the categoryHelp on _perfMonCategory shows up as null
although I am passing in a string ColorPaletteHelpString.  In addition, the
Log call to dump newData.CounterType and newData.CounterHelp fails with
exception "Category does not exist", although I can see it in the debugger
after the .Create call just above.

I am beginning to suspect that this area of .Net 1.1 is what is sometimes
referred to as  a "bug farm".  Is this one also expected to be fixed in .Net
2.0?  Are there any other known bugs I need to look out for?

Another comment - it looks to me like the PerformanceCounterCategory class
may use a single named mutex "netfxperf.1.0" to control access to all .Net
custom counters.  The SWI team would probably be interested in this, since
these are trivial to squat on and deny access to legitimate users, without
proper security controls.