[R] Coordinate projection with proj4R: the Albers Equal-Area Conic projection?

[Slist]

Hi all!

I am trying to project coordinates collected by GPS collars. The data is in 
decimal degrees and provides locations for two Sable antelope running 
around in Kruger NP South Africa.

After a wide search it seems that proj4R provides most options for 
projection of coordinates. However I can not get around the following error 
message when I try to project my coordinates using the Albers Equal Area 
Conic projection.

According to the proj4 pages, the following parameters should be supplied:
http://www.remotesensing.org/geotiff/proj_list/albers_equal_area_conic.html
PROJ.4 Organization
   +proj=aea   +lat_1=Latitude of first standard parallel
               +lat_2=Latitude of second standard parallel
               +lat_0=Latitude of false origin
               +lon_0=Longitude of false origin
               +x_0=Easting of false origin
               +y_0=Northing of false origin

But when running the command in R, I get the following error message

 > library(proj4R)
 >
 > res <- project(cbind(x, y),  "+proj=aea +lon_0=24 +lat_0=0 +lat_1=18s 
+lat_2=32s +x_0=0 +y_0=0 ") #
Error in project(cbind(x, y), "+proj=aea +lon_0=24 +lat_0=0 +lat_1=18s 
+lat_2=32s +x_0=0 +y_0=0 ") :
         major axis or radius = 0 or not given
 >

I have also tried:
 > res <- project(cbind(x, y),  "+proj=aea +lon_0=24 +lat_0=0 +lat_1=-18 
+lat_2=-32 +x_0=0 +y_0=0 ") #
with the same error.

Any suggestions?

Thanks,

Sander.