[R] cannot allocate memory

[DumpsterBear]

I am getting "Error: cannot allocate vector of size 197 MB".
I know that similar problems were discussed a lot already, but I
didn't find any satisfactory answers so far!

Details:
*** I have XP (32bit) with 4GB ram. At the time when the problem
appeared I had 1.5GB of available physical memory.
*** I increased R memory limit to 3GB via memory.limit(3000)
*** I did gs() and got
                used  (Mb) gc trigger   (Mb)  max used   (Mb)
Ncells    147534   4.0     407500   10.9    407500   10.9
Vcells 104939449 800.7  186388073 1422.1 185874684 1418.2

The garbage collection didn't help.

Any ideas? Many thanks in advance!

-- Adam