Software Deployment

Hi all
Excuse my english, please.
Why WiseScript CustomActions are so extremly slowly?
So far I used SMS Installer EXEs in my Windows Installer MSIs. The time in execution increases by 450% when I use WiseScript-CustomActions! The code from SMS-Installer IPFs and WiseScript WSEs are the same, is smart and have no direct interaction with Windows Installer (without "Get/Set Windows Installer Property"). No special options are set and "Create SmartPatch Updates" are not marked.
I have made comparisons with nearly empty scripts, only with Parsing, SET Variables, Parsing variables, Get Env. Variables, Insert Lines into TextFile, etc, but without really installation of Files. In my environment (clear machine, W2K) a equivalent sms-Installer exe need 1.9 seconds for executing within Windows Installer in deferred mode. The same Script compiled with "Wise Installation System 9" need 0.81 seconds. And a WiseScript EXE need 9 seconds!!! This is 10 times slower than with WIS9!
(If a use "Execute Program From Destination" in "Wise Windows Installer Editor" instead of "Run WiseScript from Installation/Destination" then I have no significant changes from this situation.).

Is this normal? Are WiseScript-EXEs so terrible slowly? Or can I speed-up there with special options? Why Altiris can say "WiseScript is fast"?

(I use WiseScript Package Editor 7)