R CMD INSTALL works but not install.packages ...

Hi, All;

I tried to install exon.pmcdf_1.1.tar.gz package using install.packages()
but it didn't with the following messages:

> install.packages('/Users/thchung/Downloads/exon.pmcdf_1.1.tar.gz',
repos=NULL)
Error in gzfile(file, "r") : cannot open the connection
In addition: Warning message:
In gzfile(file, "r") :
  cannot open compressed file 'exon.pmcdf_1.1.tar.gz/DESCRIPTION', probable
reason 'No such file or directory'
> sessionInfo()
R version 2.7.2 beta (2008-08-16 r46368)
i386-apple-darwin9.4.0

locale:
C

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

other attached packages:
 [1] exonmap_1.6.05       plier_1.10.0         RMySQL_0.6-0
 [4] DBI_0.2-4            RColorBrewer_1.0-2   simpleaffy_2.16.0
 [7] gcrma_2.12.1         matchprobes_1.12.0   genefilter_1.20.0
[10] survival_2.34-1      affy_1.18.2          preprocessCore_1.2.1
[13] affyio_1.8.0         Biobase_2.0.1