Thrashing?

Does R do its own swapping out to disk?  I disabled Linux swapping and 
the system still gets stuck in Purgatory where there's little CPU 
activity but the disk goes like crazy.  That's with R having almost the 
whole machine to itself and running a memory hungry compute only function.

I've seen this behavior with other version numbers but I'm running R 
2.0.0 under Fedora Core 3.  The system is a laptop with 1 Gig. RAM.

Thanks!