Do not be concerned if you see something like this in the console:
9/7/09 12:27:13 PM .... Performance: Please update this scripting addition to supply a value for ThreadSafe for each event handler: "/Users/myusername/Library/ScriptingAdditions/textsoapSA.osax"
The message is harmless and simply serves as a warning. Unfortunately, Apple did not provide a backward compatible solution to resolve this issue. Fixing the console warning problem in 10.6 would require making the scripting addition 10.6 only and breaking it under 10.5. Or require two separate additions, one for 10.5 and one for 10.6.
TextSoap 6 added support to directly script the "textsoapAgent", removing the need for the scripting addition altogether.
If you want to rid yourself of the warnings, the easiest solution to the warning messages is to disable the TextSoap scripting addition in Preferences > Plugins. Instead, take advantage of the textsoapAgent scripting options which are also much richer than the scripting addition.