This is minor, but also happened in 494. The trace file for ModDev is being created in "C:\Program Files\rFactor2\ModDev\UserData\Log" as opposed to "C:\Documents and Settings\UserName\My Documents\rFactor2\ModDev\UserData\Log"
If it helps more info: my last trace to show up in Documents and Settings was dated 2/15/2013. Even if they've always generated into Core, is it really the correct place for them to be created? Intuitively I looked in "Documents", I was a bit confused why nothing was changing until I looked at time stamps, then looked in "Core".
+1, btw trace=3 seems to be enabled by default and has been for a few builds now (well for me it has). It seems in B660 a similar fate has befallen the ModDev config.ini file but with an added twist! The 1st time you run ModDev its config.ini gets created in the root rF2 folder (where the launcher EXE is). Any changes you make on the 'Video Res' tab causes a 2nd config.ini to be created in ModDev\UserData. Also I noticed the initial config.ini has HDR enabled by default but in the 2nd config.ini it gets disabled requiring you to edit the file if you want it back on.