[R] Warning messages about replacing previous import...

[Petar Milin]

Hello!
I have posted this message before, but no answer. Now, after a few 
upgrades, I still have the same warning messages. I am a bit worried, 
since I do not know does this affect or could affect R. I use R under 
Linux (Ubuntu 6.06).
After start, and after loading few libraries, I got following message:

Warning messages:
1: In namespaceImportFrom(self, asNamespace(ns)) :
replacing previous import: cov2cor
2: In namespaceImportFrom(self, asNamespace(ns)) :
replacing previous import: xtabs

Is this harmful? Can I do something to fix that?

Sincerely,
PM