SNA Server Access Violation in Function S1PWLUSE()

SYMPTOMS

Application exception occurred:
        App: exe\snaservr.DBG (pid=<process ID>)
        When: <data> @ <time>
        Exception number: c0000005 (access violation)

function: s1pwluse
        003ebb91 7514             jnz     s1pwluse+0xa7 (003ebba7)
        003ebb93 66c746180100     mov     word ptr [esi+0x18],0x1
ds:00f0ea07=????
        003ebb99 6a00             push    0x0
        003ebb9b e880060000       call    s1pwclps (003ec220)
        003ebba0 b101             mov     cl,0x1
        003ebba2 e9d9010000       jmp     s1pwluse+0x280 (003ebd80)
        003ebba7 663d1a00         cmp     ax,0x1a
        003ebbab 0f85cf010000     jne     s1pwluse+0x280 (003ebd80)
        003ebbb1 b101             mov     cl,0x1
        003ebbb3 e9c8010000       jmp     s1pwluse+0x280 (003ebd80)
FAULT ->003ebbb8 668b4618         mov     ax,[esi+0x18]
ds:00f0ea07=????
        003ebbbc 663d0100         cmp     ax,0x1
        003ebbc0 751a             jnz     s1pwluse+0xdc (003ebbdc)
        003ebbc2 66c746181500     mov     word ptr [esi+0x18],0x15
ds:00f0ea07=????
        003ebbc8 668b420c         mov     ax,[edx+0xc]
ds:021ea5c3=????
        003ebbcc 6689460e         mov     [esi+0xe],ax
ds:00f0ea07=????
        003ebbd0 e8eb040000       call    s1pwolpq (003ec0c0)
        003ebbd5 b101             mov     cl,0x1
        003ebbd7 e9a4010000       jmp     s1pwluse+0x280 (003ebd80)
        003ebbdc 663d1a00         cmp     ax,0x1a
        003ebbe0 0f859a010000     jne     s1pwluse+0x280 (003ebd80)
        003ebbe6 b101             mov     cl,0x1

*----> Stack Back Trace <----*

FramePtr ReturnAd Param#1  Param#2  Param#3  Param#4  Function Name
000000ff 00000000 00000000 00000000 00000000 00000000 snaservr!s1pwluse
(FPO: [1,0,2])
000000ff 00000000 00000000 00000000 00000000 00000000 snaservr!<nosymbols>
				

   Event ID: 624
   Source: SNA Server
   Description: Creating dump file <snaroot>\traces\snadump.log for
                snaservr.exe.