[BioC] se.exprs extractor question

[Kellie J. Archer, Ph.D.]

I am wanting to directly use the p-values estimated from mas5calls, and 
following the example,

 > data(affybatch.example)
 > PACalls <- mas5calls(affybatch.example)
Getting probe level data...
Computing p-values
Making P/M/A Calls
 > se.exprs(PACalls)[1:10,]
Error in function (classes, fdef, mtable)  :
        unable to find an inherited method for function "se.exprs", for 
signature "ExpressionSet"

In previous releases the p-values were stored in se.exprs, and the help 
still indicates that is the case. Does anyone know how they can be 
extracted?
 > sessionInfo()
R version 2.5.0 (2007-04-23)
i386-pc-mingw32

locale:
LC_COLLATE=English_United States.1252;LC_CTYPE=English_United 
States.1252;LC_MONETARY=English_United 
States.1252;LC_NUMERIC=C;LC_TIME=English_United States.1252

attached base packages:
[1] "tools"     "stats"     "graphics"  "grDevices" "utils"     "datasets"
[7] "methods"   "base"    

other attached packages:
    affy   affyio  Biobase
"1.14.1"  "1.4.0" "1.14.0"

-Kellie Archer