[BioC] Does old workspace work?

[Loren Engrav]

> sessionInfo()
R version 2.8.0 Patched (2008-10-26 r46783)
i386-apple-darwin9.5.0

locale:
en_US.UTF-8/en_US.UTF-8/C/C/en_US.UTF-8/en_US.UTF-8

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

other attached packages:
[1] simpleaffy_2.18.0  genefilter_1.22.0  survival_2.34-1    affyio_1.10.0
porcinecdf_2.3.0   gcrma_2.14.0       matchprobes_1.14.0 affy_1.20.0
Biobase_2.2.0     

loaded via a namespace (and not attached):
[1] AnnotationDbi_1.4.0  DBI_0.2-4            RSQLite_0.7-1
annotate_1.20.0      preprocessCore_1.4.0

==============
A year or so ago I ran 64bit R on Mac PPC and saved various workspaces

Now am running 64bit R on Intel 2x3.2 QuadCore and MacOS 10.5.5

I load up the old workspaces
and I enter

> write.exprs(ABeset_gcrma, file="ABeset_gcrma081028orig.txt")
Where ABeset_gcrma is an old file

and I get
Error in function (classes, fdef, mtable)  :
unable to find an inherited method for function "write.exprs", for signature
"exprSet"

And I enter
> exprs2excel(ABeset_gcrma, file="ABeset_gcrma081028v2.csv")

And I get
Error: could not find function "exprs2excel"

Am I doing something wrong?

Thank you