[R] Memory leak in R v1.6.0?

[apollo wong]

I have a function that needs to be repeated many times
with for loop. I have take measure to rm all the big
arrays that was used in the function. The only array
that cannot be rm was the return arrays. The loop
needed to be repeat for over 2000 times and I am using
v1.6.0 in Windows 2000
 When I look at the task manager, I see that the
memory used by R keep going up and reach more than 1G
byte after 700 iteration or so. I have try including
gc after every loop. No help at all. I'll appreciate
any suggestion. 
 What is the command to free up unused memory in R
other than relying on automatic garbage collection? Is
there a free command in R?
 Thanks
Apollo Wong