Question about virtualbox

[jerry]

I just installed the PUEL version of virtualbox and everything seems to 
be working fine but I have a question about using the shared folder.
The shared folder is in my /home/jerry/ directory and I can access it in 
my guest OS (windows xp). I don't know if it is still true but I always 
heard that linux can read and write to the windows file system but 
windows cannot safely read and write to ext3. I did google for windows 
reading and writing to ext3 and there is a utility that they say can 
safely do it.
My question is: Can I use my guest OS (XP) to read and write the shared 
folder on the ext3 file system safely? Should I install the xp utility 
to enable the read/write? Any precautions that I need to take? I have 
backed up /home/ but I would hate to have to reformat the whole partition.
Thanks for any advice.
Jerry