In standard/installed builds logging is switched off.
To enable logging you have to create a folder /Beta/ in the root of IM
putting in psrp.js and user.config (template is user.config.350)
with just this two lines in user.config
Code:
// what to log and what not, possible values are: all, trace, info, warn, error
config.defaultLogLevel = "trace";
// where to log
config.logFile = "/Data/prsp_script.log";
Hope I got this correct, out of memory