Hi Pete, This is just to tell you that I should have finally get rid of most of the problems affecting TXNetFile in asynchronous mode; the version now in the CVS head should be OK for the tests you wanted to do. To activate the asynchronous mode you should set XNet.GoAsynchronous: 1 in the .rootrc file. I should also have solved the problems related to the destruction of the GarbageCollectorThread (once you mentioned something to me about this). This thread is now disabled by default. To start it XNet.StartGarbageCollectorThread 1 Please let me know if you give a try. Gerri