Here's the console logs after following the instructions above:
11/10/2012 21:29:35 PCMonitor[298] YAJL JSON framework found
11/10/2012 21:29:35 /Library/PrivilegedHelperTools/com.mobilepcmonitor.PCMonitorHelper[301] PCMonitorHelper launched (uid: 0, euid: 0, pid: 301)
11/10/2012 21:29:35 /Library/PrivilegedHelperTools/com.mobilepcmonitor.PCMonitorHelper[301] PCMonitor 1.3 is starting...
11/10/2012 21:29:36 /Library/PrivilegedHelperTools/com.mobilepcmonitor.PCMonitorHelper[301] Configuration loaded for account (null)
After relaunch the app seems to forget my login details too.