I downloaded Red Hat Enterprise Linux 5.7 and 5.9 and loaded them into separate VMs.  I then created profiles for both of these systems using the instructions provided.  However, when trying to run linux_pslist (and pslist) using the profiles, I am still seeing an incompatibility profile issue.  The VM of the snapshot I have is Red Hat Enterprise Linux Server 2.6.18.274.el5.  The profile I created using 5.7 is the same kernel as my target VM.  (Note:  I was unable to create this profile directly from the target VM)
# python vol.py --info | grep Linux
Volatile Systems Volatility Framework 2.3_beta
LinuxCentOS63x64               - A Profile for Linux CentOS63 x64
LinuxFedora17x64               - A Profile for Linux Fedora17 x64
LinuxMandriva2011x64           - A Profile for Linux Mandriva2011 x64
LinuxOpenSuSE12x86             - A Profile for Linux OpenSuSE12 x86
LinuxRHEL57x64                 - A Profile for Linux RHEL57 x64
LinuxRHEL59x64                 - A Profile for Linux RHEL59 x64
LinuxUbuntu1204x64             - A Profile for Linux Ubuntu1204 x64
linux_yarascan          - A shell in the Linux memory image
# python vol.py -f server_vmsn.raw --profile=LinuxRHEL57x64 linux_pslist 
Volatile Systems Volatility Framework 2.3_beta
*** Failed to import volatility.plugins.addrspaces.legacyintel (AttributeError: 'module' object has no attribute 'AbstractWritablePagedMemory')
Offset             Name                 Pid             Uid             Gid    DTB                Start Time
------------------ -------------------- --------------- --------------- ------ ------------------ ----------
No suitable address space mapping found
Tried to open image as:
 MachOAddressSpace: mac: need base
 LimeAddressSpace: lime: need base
 WindowsHiberFileSpace32: No base Address Space
 WindowsCrashDumpSpace64: No base Address Space
 HPAKAddressSpace: No base Address Space
 VirtualBoxCoreDumpElf64: No base Address Space
 VMWareSnapshotFile: No base Address Space
 WindowsCrashDumpSpace32: No base Address Space
 AMD64PagedMemory: No base Address Space
 IA32PagedMemoryPae: No base Address Space
 IA32PagedMemory: No base Address Space
 MachOAddressSpace: MachO Header signature invalid
 LimeAddressSpace: Invalid Lime header signature
 WindowsHiberFileSpace32: PO_MEMORY_IMAGE is not available in profile
 WindowsCrashDumpSpace64: Header signature invalid
 HPAKAddressSpace: Invalid magic found
 VirtualBoxCoreDumpElf64: ELF64 Header signature invalid
 VMWareSnapshotFile: Invalid VMware signature: 0xf000ff53
 WindowsCrashDumpSpace32: Header signature invalid
 AMD64PagedMemory: Failed valid Address Space check
 IA32PagedMemoryPae: Incompatible profile LinuxRHEL57x64 selected
 IA32PagedMemory: Incompatible profile LinuxRHEL57x64 selected
 FileAddressSpace: Must be first Address Space
 ArmAddressSpace: Failed valid Address Space check
Any ideas??  Also I can share both of the profiles if someone wants them.