R help - Dec 2007 - odd error messages coming from val.prob() {Design}

Hi,

after upgrading my R install from 2.5 -> 2.6.1 and performing multiple 
iterations of update.packages(), I am getting an odd error when trying to 
plot a calibration curve from the val.prob() function in package Design.

when running this function (which used to work) I get the following error 
message:

Error in .C("lowess", x = as.double(xy$x[o]), as.double(xy$y[o]), n, 
as.double(f),  : 
  C symbol name "lowess" not in DLL for package "base"

Here is my relevent session info:

R version 2.6.1 (2007-11-26) 
i686-pc-linux-gnu 

locale:
LC_CTYPE=en_US.UTF-8;LC_NUMERIC=C;LC_TIME=en_US.UTF-8;LC_COLLATE=en_US.UTF-8;LC_MONETARY=en_US.UTF-8;LC_MESSAGES=en_US.UTF-8;LC_PAPER=en_US.UTF-8;LC_NAME=C;LC_ADDRESS=C;LC_TELEPHONE=C;LC_MEASUREMENT=en_US.UTF-8;LC_IDENTIFICATION=C

attached base packages:
[1] splines   stats     graphics  grDevices utils     datasets  methods  
[8] base     

other attached packages:
 [1] e1071_1.5-17   class_7.2-38   lattice_0.17-2 Cairo_1.3-5    ROCR_1.0-2    
 [6] gplots_2.3.2   gdata_2.3.1    gtools_2.4.0   Design_2.1-1   survival_2.34 
[11] Hmisc_3.4-3   

loaded via a namespace (and not attached):
[1] cluster_1.11.9  grid_2.6.1      rcompgen_0.1-17


Any ideas?

cheers,

Dylan



-- 
Dylan Beaudette
Soil Resource Laboratory
http://casoilresource.lawr.ucdavis.edu/
University of California at Davis
530.754.7341