How much ram clone cd needs

[So_SIMPLE]

When i was trying to copy from cd-rom to image and then to disk my system stopped at 7%
i restarted t and it wrote tup to 19%
i have 64mb ram . In help the say that it requires 32 mb . Other programms use only 10% of my total memory actually 6,4 mb. Why after a while clobne cd stop responding???? What's the problem really??? what should i do??? i toasted about 9disks and it wrote successfully a cd-rw.
Why that happens only with a cd-r????