Originally Posted By: Virtual1
Oh I tried escaping, double escaping, alternate ways to express spaces (\x20 etc) and a whole bunch of other things $(echo ...) before finally giving up on it.

Well, i located an expendable flash drive... but i don't encounter any such problem:

Code:
$ cat dsr

diskutil partitionDisk /dev/disk1 2 APM JHFS+ abc 480M JHFS+ 'def ghi' R


$ bash -x dsr
+2: diskutil partitionDisk /dev/disk1 2 APM JHFS+ abc 480M JHFS+ 'def ghi' R
Started partitioning on disk1
Unmounting disk
Creating partition map
Waiting for disks to reappear
Formatting disk1s2 as Mac OS Extended (Journaled) with name abc
Formatting disk1s4 as Mac OS Extended (Journaled) with name def ghi
Finished partitioning on disk1
/dev/disk1
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:     Apple_partition_scheme                        *2.0 GB     disk1
   1:        Apple_partition_map                         32.3 KB    disk1s1
   2:                  Apple_HFS abc                     480.0 MB   disk1s2
   3:                  Apple_HFS def ghi                 1.4 GB     disk1s4

$ echo $?
0


Edit and try again...
Code:
$ date; sw_vers
Fri Jun  3 13:17:09 EDT 2011
ProductName:	Mac OS X
ProductVersion:	10.6.7
BuildVersion:	10J869


$ cat dsr
alpha=Service\ Lion
bravo=Service\ Snow
charlie=Service\ Leopard

diskutil partitionDisk /dev/disk1 3 APM JHFS+ "$alpha" 480M \
JHFS+ "$bravo" 480M JHFS+ "$charlie" R


$ bash -x dsr
+1: alpha='Service Lion'
+2: bravo='Service Snow'
+3: charlie='Service Leopard'
+5: diskutil partitionDisk /dev/disk1 3 APM JHFS+ 'Service Lion' 480M \
JHFS+ 'Service Snow' 480M JHFS+ 'Service Leopard' R
Started partitioning on disk1
Unmounting disk
Creating partition map
Waiting for disks to reappear
Formatting disk1s2 as Mac OS Extended (Journaled) with name Service Lion
Formatting disk1s3 as Mac OS Extended (Journaled) with name Service Snow
Formatting disk1s4 as Mac OS Extended (Journaled) with name Service Leopard
Finished partitioning on disk1
/dev/disk1
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:     Apple_partition_scheme                        *2.0 GB     disk1
   1:        Apple_partition_map                         32.3 KB    disk1s1
   2:                  Apple_HFS Service Lion            480.0 MB   disk1s2
   3:                  Apple_HFS Service Snow            480.0 MB   disk1s3
   4:                  Apple_HFS Service Leopard         1.0 GB     disk1s4


$ df -h |sed '1p;/disk1/!d'
Filesystem      Size   Used  Avail Capacity  Mounted on
/dev/disk1s2   458Mi   19Mi  439Mi     5%    /Volumes/Service Lion
/dev/disk1s3   458Mi   19Mi  439Mi     5%    /Volumes/Service Snow
/dev/disk1s4   1000i   32Mi  968Mi     4%    /Volumes/Service Leopard


Works fine with no special quoting or escaping tricks. All those volumes look right in Finder too.

::shrug::

With which OS are you running your failing script?