Problem with NSIS and RegAsm.exe

[fantasio]

Hi, i browsed through the Forums, read the Manual but i can't find a solution.

I have the following lines in my NSIS Script:

...
push "v2.0"
call GetDotNetDir
;pop $R0
GetFullPathName /SHORT $1 $R0
GetFullPathName /SHORT $2 $INSTDIR
StrCpy $0 '"$1\RegAsm.exe" "$2\IPKTools.dll" /codebase'
DetailPrint $0
nsExec::ExecToLog $0
pop $0
...

It never works. The Installlog says:
"C:\WINDOWS\MICROS~1.NET\FRAMEW~1\V20~1.507\RegAsm.exe" "C:\PROGRA~1\IPKTOO~2\IPKTools.dll" /codebase
Microsoft (R) .NET Framework Assembly Registration Utility 2.0.50727.42
Copyright (C) Microsoft Corporation 1998-2004. All rights reserved.

RegAsm : warning RA0000 : Registering an unsigned assembly with /codebase can cause your assembly to interfere with other applications that may be installed on the same computer. The /codebase switch is intended to be used only with signed assemblies. Please give your assembly a strong name and re-register it.
RegAsm : error RA0000 : An error occurred inside the user defined Register/Unregister functions: System.NullReferenceException: Object reference not set to an instance of an object.
at IPKTools.SwAddin.RegisterFunction(Type t)

But if i use Regasm after the failed Installation from the Windowsshell it works! I use: regasm /codebase ipktools.dll and the error is missing. I cant' get rid of the Warning because my .dll depends on some unsigned dlls so i can't sign it strongly.

What is wrong there ? Nedd help!

Thanks in advance, fanta