I have an issue with NDPS on my NW6.5sp7 server.
The manager is reporting BAD and the latest NDS Events file reads:

27/08/10 9:58:36 , Error (-601) was returned, Operation "Get Effective Rights". Replica on server 'MY-SERV', Object Name: .printer1.Printers.Promzona.NES
27/08/10 9:58:36 , Error (-601) was returned, Operation "Get Effective Rights". Replica on server 'MY-SERV', Object Name: .printer2.Printers.Promzona.NES
27/08/10 9:58:36 , Error (-601) was returned, Operation "Get Effective Rights". Replica on server 'MY-SERV', Object Name: .printer3.Printers.Promzona.NES
27/08/10 9:58:36 , Error (-601) was returned, Operation "Get Effective Rights". Replica on server 'MY-SERV', Object Name: .printer4.Printers.Promzona.NES

and so every 15 seconds. only these 4 printers from 45
Before was all o'key
NDS health check procedures indicates no errors in tree
I have been searching around for a fix to no avail.
I found a solution only for a similar error -672, but not for -601

Any help is appreciated.
Thank You