Using dialogs in RTC

hi all,

i have a function which does create some records anywhere in my database based on the parent record. I call this function in a page from the action pane (function called in menu item/OnAction trigger). In my function there is a local dialog variable named Window.

Window.OPEN([...]);
[...]
Window.Update([...]);
[...]
Window.Close;

The RTC seems to have a problem with this dialog because everytime i call my function the client crashes. I analysed my function in cs but i dont get what is wrong. The event log on the service tier displays the following:

Event Type: Error
Event Source: MicrosoftDynamicsNAVServer
Event Category: None
Event ID: 0
Date: 16.12.2008
Time: 16:40:55
User: Nicht zutreffend
Computer: ***-3TIER
Description:
User: ***
Type: System.MissingMethodException
Message: The method Microsoft.Dynamics.Nav.BusinessApplication.Page5018334.Control132_OnAction could not be found.
StackTrace:
bei Microsoft.Dynamics.Nav.Runtime.NavApplicationMethod.InvokeMethod(Object obj, String methodName, Object[] args)
bei Microsoft.Dynamics.Nav.Service.NSField.ActionField(NavConnection con)
bei Microsoft.Dynamics.Nav.Service.NSService.<>c__DisplayClass1c.<ActionField>b__1b(Connection connection)
bei Microsoft.Dynamics.Nav.Service.NSService.ExecuteOperation[T](String operationName, ServiceOperation`1 operation, Connection connection, WindowsIdentity impersonationIdentity)
Source: Microsoft.Dynamics.Nav.Ncl

Is there any rule which I have to notice for RTC with dialogs? In Classic Client it runs all fine. If I don't use the dialog in my function also the RTC does fine. Would be great to get a hint...