Hey David,
I wish I could stop bothering but even running RGui is not working.
I did as you have told me and I still get the same error message:
"Warning messages:
1: In tclRequire("dde") : Tcl package 'dde' not found
2: In tclRequire("dde", warn = TRUE) : Tcl package 'dde' not found
Error in structure(.External(.C_dotTclObjv, objv), class = "tclObj") :
[tcl] invalid command name "cget"."
So, I restarted the software and first installed the dde package, which went well, then tried running the NMBU under library(Rcmdr) from the RCommander tool window and I get the same c***! Tried only installing the RcmdrPlugin.NMBU... same c***!
I just feel like I am trying to solve the QCD Lagrangian equation using an abacus 
Is this a cosmic conspiracy?
Anyhow... if you know any other way/package to run a Post hoc pairwise comparison (Fisher/LSD) I would be pleased to try, because so far I think our good friends at NMBU don't want me using their plugin.
Thanks and Cheers.