[R] Request for help re. opening workspace

[Clough, Helen]

Dear all,
 
I am wondering if someone can help me out of a pickle - forgive me if
there is an obvious solution to the following - I am not very proficient
in the more technical aspects of R. 
 
I am working with a large data set in R, which for reasons of
housekeeping I normally remove upon finishing a session and read in
again at the next start-up, seeking to avoid problems with huge
workspaces. However, rather stupidly last time I forgot to do this, and
closed the session, which saved without complaint. However, now when I
try to start up, I get the following message:
 
Error: cannot allocate vector of size 2023kb
In addition: Warning messages:
1: Reached total allocation of 1536Mb: see help(memory.size)
2: Reached total allocation of 1536Mb: see help(memory.size)
 
followed by a window with a button which says
 
Fatal error: unable to restore saved data in .RData
 
and when I click "OK" obviously everything shuts down.
 
Is there anything I can do to resolve this?? The workspace itself
appears to be just over 100MB. I do have two backups, but I suspect that
the most recent one may be subject to the same problem, and the other is
rather older. I do have my routines etc. saved outside R but would
rather avoid a tedious process of re-entering code if I can.
 
Many thanks - all suggestions gratefully received,
 
Helen Clough
Lecturer in Risk Analysis,
National Centre for Zoonosis Research,
University of Liverpool