[R] memory problem with mac os X

[Edouard Henrion]

Dear list,

I am using R.2.0.1 on a G5 biprocessor 2.5GHz with 2Go RAM (Mac OS X 
10.3.8).

I'm trying to calculate an object of type "dist". I am getting the 
following memory error :

*** malloc: vm_allocate(size=1295929344) failed (error code=3)
*** malloc[25960]: error: Can't allocate region
Error: cannot allocate vector of size 1265554 Kb

When I do a top on the terminal, I can see that this size has already 
been allocated... It seems that R tries to allocate the memory twice.
Does anybody have an advice about this ?

Thanks,

Edouard Henrion