Slow Browsing N/W servers w NT Explorer

Is anyone aware of an issue with the speed of browing netware servers with Windows NT Explorer. There used to be an issue that was fixed with a replacement of the MUP.SYS file, and was solved since the implementation of Client 4.3 (Netware) and Service Pack 4 (NT).

Unfortunately this issue seems to have returned, even though I am now running Netware Client 4.6 SP1 and NT 4.0 Service Pack 6.

Has anyone run across this and do you have a solution?????