"out of vmalloc space" cloop error message with Knoppix 5.1.1

[Gilles van Ruymbeke <gvr_knoppix_mailing_list_no_spam_123@ruymbeke.com>]

Hello,
On a re-mastered Knoppix 5.1.1 DVD I have the following error message:
"allocation failed: out of vmalloc space - use vmalloc=<size> to increase size"
If I use a smaller amount of memory in the system or if I mount a 
smaller number
of cloop files (I have a total of 5) everything is just fine.
(I use extra cloops files to customize the dvd)
What do I need to do in order to fix this problem  ?
Best Regards,
Gilles