I solved my own problem:
in the file inc_header.asp
I found this code
if strRequireReg = "1" and strDBNTUserName = "" then
if not Instr(strScriptName,"policy.asp") > 0 and _
not Instr(strScriptName,"register.asp") > 0 and _
not Instr(strScriptName,"password.asp") > 0 and _
not Instr(strScriptName,"faq.asp") > 0 and _
not Instr(strScriptName,"login.asp") > 0 then
and changed it to this code
if strRequireReg = "1" and strDBNTUserName = "" then
if not Instr(strScriptName,"policy.asp") > 0 and _
not Instr(strScriptName,"register.asp") > 0 and _
not Instr(strScriptName,"password.asp") > 0 and _
not Instr(strScriptName,"guestbook.asp") > 0 and _
not Instr(strScriptName,"faq.asp") > 0 and _
not Instr(strScriptName,"login.asp") > 0 then
Maybe this will help someone else with a similar problem
PS great forums and mod - really really love it guys.