Error "Train dataset for temp stage can not be filled." while using traincascade tool of OpenCV
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I'm building the opencv_traincascade.exe tool from source code (OpenCV 2.4.0) using vs2010 on windows 7. I want to train a LBP classifier, so I'm using opencv_traincascade.exe with the following arguments 

> -data D:\OpenCV\Classifiers\lbpclassifier1\temp\data -vec D:\OpenCV\Classifiers\lbpclassifier1\temp\samples.vec -bg
> D:\OpenCV\Classifiers\lbpclassifier1\temp\negative\infofile.txt
> -numPos 40 -numNeg 40 -precalcIdxBufSize 500 -precalcValBufSize 500 -stageType BOOST -featureType LBP -w 24 -h 24

The error message that I get is:

    PARAMETERS:
    cascadeDirName: D:\OpenCV\Classifiers\lbpclassifier1\temp\data
    vecFileName: D:\OpenCV\Classifiers\lbpclassifier1\temp\samples.vec
    bgFileName: D:\OpenCV\Classifiers\lbpclassifier1\temp\negative\infofile.txt
    numPos: 2
    numNeg: 40
    numStages: 20
    precalcValBufSize[Mb] : 500
    precalcIdxBufSize[Mb] : 500
    stageType: BOOST
    featureType: LBP
    sampleWidth: 24
    sampleHeight: 24
    boostType: GAB
    minHitRate: 0.995
    maxFalseAlarmRate: 0.5
    weightTrimRate: 0.95
    maxDepth: 1
    maxWeakCount: 100
    
    ===== TRAINING 0-stage =====
    <BEGIN
    POS count : consumed   2 : 2
    Train dataset for temp stage can not be filled. Branch training terminated.

This question has been asked before : http://stackoverflow.com/questions/9973813/error-while-using-opencv-train-cascade 
, and the solution suggested there viz. making the number of positive and negative samples equal doesn't help in this case.

I thought that the error might be related to this bug : http://code.opencv.org/issues/1834
So, I downloaded the latest release of imagestorage.cpp from that page and rebuilt the opencv_traincascades tool. 
Also, the total number of samples in the .vec file is 45. So as suggested in this [comment](http://code.opencv.org/issues/1834#note-8) I have changed the numPos argument to 2, so that I don't run out of samples in the .vec file. The number of samples in the .vec file is 45.

Any help is much appreciated. Thanks.