after you said all these i actually removed my old appswitch extension and installed it again.
The version is appswitch 1.03 i downloaded it from the same link signed it using symbian opensign with all caps.
Then installed it and it is working fine both in the scripts and the interactive shell.
My device in N95 8GB.
I am not getting whats going different at yourside.
and yes aaaaapo has mentioned a very valid point please check that