No problem, Smak. The script in question is probably explicitly checking for some specific property of the Windows Script Host that is not exactly the same as in the OnScript Host (such as the version number).
You have probably not noticed, but the OnScript Editor by default runs scripts on it's own internal OnScript Host not the Windows Script Host. This is mainly for better integration with the editor as well as for debugging. Most operations are completely compatible, but there are obvious differences, like the application name and the version numbers.
To make a long story short, you have two options: in the editor check the "Run in separate process (WSH)" box - this will force OnScript to run the script in the Windows Script Host. Or figure out what the script is doing and program around that. Most likely it is checking the WScript.Version property and comparing it with a constant as in :
If WScript.Version < 5.6 Then ...
Feel free to post any part of your script here, it should not be too difficult to spot the offending statements.
XLnow - the makers of OnScript