Hi
I have the same problem, but just for NTFS filesystem, on my FAT32 it works fine.
I solved the problem in FAT32 by creating a IUSR_COMPUTERNAME and givig it rights in the catalog that contains the sessionfiles.
But as I said it don't work on NTFS or I have done it wrong.
I have tried to set readrights for the IUSR user to php.ini alswell.
So I also need help... plz.
/Andreas