[R] Error in opening .RData containing a genefilter object

[David Ruau]

Hi,
I discover that when I save a workspace containing a genefilter (pkg 
from Bioconductor) object I cannot open no more after. I have to 
restore the .RData file from a backup to be able to start R again.
I didn't upgrade to Version 2.2 but I'm not sure that it will solve the 
problem.
Did anyone have encounter the same problem?
Below is a short r session to reproduce the error:
...
[Previously saved workspace restored]

 > library(genefilter)
Loading required package: Biobase
Loading required package: tools
Welcome to Bioconductor
          Vignettes contain introductory material.  To view,
          simply type: openVignette()
          For details on reading vignettes, see
          the openVignette help page.
Loading required package: survival
Loading required package: splines
 > f1 <- kOverA(5, 60)
 > q()
Save workspace image? [y/n/c]: y
[computer:admin]$ r

R : Copyright 2005, The R Foundation for Statistical Computing
Version 2.1.1  (2005-06-20), ISBN 3-900051-07-0

R is free software and comes with ABSOLUTELY NO WARRANTY.
You are welcome to redistribute it under certain conditions.
Type 'license()' or 'licence()' for distribution details.

R is a collaborative project with many contributors.
Type 'contributors()' for more information and
'citation()' on how to cite R or R packages in publications.

Type 'demo()' for some demos, 'help()' for on-line help, or
'help.start()' for a HTML browser interface to help.
Type 'q()' to quit R.

Error in .initContents() : couldn't find function "isGeneric"
Error: .onLoad failed in 'loadNamespace' for 'Biobase'
Fatal error: unable to restore saved data in .RData

[gaia:admin]$
-------
I am working under OS X 10.3.9.

David