This JMP ESP does not work for me:

	0:008> lmv m kernel32
	start    end        module name
	7c800000 7c8f6000   kernel32   (pdb symbols)          c:\symbols_net\kernel32.pdb\34560E80F5C54175B208848EF863C5BD2\kernel32.pdb
	    Loaded symbol image file: C:\WINDOWS\system32\kernel32.dll
	    Image path: C:\WINDOWS\system32\kernel32.dll
	    Image name: kernel32.dll
	    Timestamp:        Sun Apr 13 19:11:24 2008 (4802A12C)
	    CheckSum:         000F44A2
	    ImageSize:        000F6000
	    File version:     5.1.2600.5512
	    Product version:  5.1.2600.5512
	    File flags:       0 (Mask 3F)
	    File OS:          40004 NT Win32
	    File type:        2.0 Dll
	    File date:        00000000.00000000
	    Translations:     0409.04b0
	    CompanyName:      Microsoft Corporation
	    ProductName:      Microsoft® Windows® Operating System
	    InternalName:     kernel32
	    OriginalFilename: kernel32
	    ProductVersion:   5.1.2600.5512
	    FileVersion:      5.1.2600.5512 (xpsp.080413-2111)
	    FileDescription:  Windows NT BASE API Client DLL
	    LegalCopyright:   © Microsoft Corporation. All rights reserved.
	0:008> u 0x7C91FCD8
	ntdll!RtlpAssemblyStorageMapResolutionDefaultCallback+0x286:
	7c91fcd8 8985c4fdffff    mov     dword ptr [ebp-23Ch],eax
	7c91fcde 8d85b0fdffff    lea     eax,[ebp-250h]
	7c91fce4 50              push    eax
	7c91fce5 6a08            push    8
	7c91fce7 8d85d8fdffff    lea     eax,[ebp-228h]
	7c91fced bf40fd917c      mov     edi,offset ntdll!RtlpTheEmptyActivationContextData+0xe8 (7c91fd40)
	7c91fcf2 50              push    eax
	7c91fcf3 c785b0fdffff18000000 mov dword ptr [ebp-250h],offset <Unloaded_pi.dll>+0x17 (00000018)