Cu.reportError("TelemetryStopwatch: key \"" +
                    aHistogram + "\" was already initialized");

While debugging my JavaScript code, I find the Error Console very useful. Besides the errors in my code, it also shows error messages about other peoples' code for sites that I have open. This is a little annoying, because I have to click "Clear" each time or else scroll down to see my error messages. To simplify matters, I closed all tabs and windows except my own window (without tabs) where I'm testing my JavaScript program. All the other error messages disappeared -- except one. This lone leftover message appears every few minutes in PINK (I guess that means it's serious) even when my program's window is the only one open, without any tabs: Timestamp: 12/14/12 11:47:39 AM Error: TelemetryStopwatch: key "FX_SESSION_RESTORE_COLLECT_DATA_MS" was already initialized Source File: resource://gre/modules/TelemetryStopwatch.jsm Line: 53 I clicked on the Source File (it's blue and underlined in the original) and up popped a source listing of some file from inside the Firefox.app package. Lines 52 and 53 read as follows: Cu.reportError("TelemetryStopwatch: key \"" + aHistogram + "\" was already initialized"); Any idea what this is about? --Gil