JMicron Raid Problems on a Gigabyte GA-P35-DS3

I have a Jmicron Controller on my Board and try to setup a Gentoo System on the Raid 0.

Board: Gigabyte GA-P35-DS3
OS: Live DVD of Fedora release 7.91 (Rawhide)
Dmraid: 
dmraid version:         1.0.0.rc14 (2006.11.08) debug 
dmraid library version: 1.0.0.rc14 (2006.11.08)
device-mapper version:  4.11.0
lspci:
03:00.0 SATA controller: JMicron Technologies, Inc. JMicron 20360/20363 AHCI Controller (rev 02)
03:00.1 IDE interface: JMicron Technologies, Inc. JMicron 20360/20363 AHCI Controller (rev 02)

dmraid -tay shows this
jmicron_GRAID           : 0 625082368 striped 2 256 /dev/sda 0 /dev/sdb 0
jmicron_GRAID           1: 0 61440000 linear /dev/mapper/jmicron_GRAID            206848
jmicron_GRAID           2: 0 501993472 linear /dev/mapper/jmicron_GRAID            61646848
jmicron_GRAID           3: 0 206785 linear /dev/mapper/jmicron_GRAID            63
jmicron_GRAID           5: 0 3951927 linear /dev/mapper/jmicron_GRAID            563640383
jmicron_GRAID           6: 0 57480712 linear /dev/mapper/jmicron_GRAID            567592373

thats ok and correct, also 
cfdisk /dev/dm-1 
shows me the correct partitions

 ls -lart /dev/mapper/
total 0
crw-rw----  1 root root  10, 63 2007-10-03 16:28 control
brw-rw----  1 root disk 253,  0 2007-10-03 16:28 live-rw
brw-------  1 root root 253,  1 2007-10-03 20:49 jmicron_GRAID           
drwxr-xr-x  2 root root     100 2007-10-03 20:57 .
drwxr-xr-x 13 root root    8580 2007-10-03 20:58 ..

But the jmicron_GRAID has a lot of spaces at the end of the filename.

If I try a
dmraid -ay 
dmesg shows me this:
device-mapper: table: 253:2: linear: dm-linear: Device lookup failed
device-mapper: ioctl: error adding target to table
device-mapper: table: 253:2: linear: dm-linear: Device lookup failed
device-mapper: ioctl: error adding target to table
device-mapper: table: 253:2: linear: dm-linear: Device lookup failed
device-mapper: ioctl: error adding target to table
device-mapper: table: 253:2: linear: dm-linear: Device lookup failed
device-mapper: ioctl: error adding target to table
device-mapper: table: 253:2: linear: dm-linear: Device lookup failed
device-mapper: ioctl: error adding target to table

Maybe somebody can help me.