Cascade classifier detect multi scale always returns nothing.

edit

Hi guys, sorry to bother again.

But when I run the the detectMultiScale on a trained cascade classifier nothing is ever detect, no rectangles. Weird thing is even with just one stage i get good results using LBP here is my results.

POS count : consumed   2000 : 2000
NEG count : acceptanceRatio    4000 : 1
Precalculation time: 0.196
+----+---------+---------+
|  N |    HR   |    FA   |
+----+---------+---------+
|   1|    0.965|  0.08575|
+----+---------+---------+

and this is how i call the classifier ...

classifier.detectMultiScale(testMat, rectangles, 1.1, 0, 0, cv::Size(30, 30), cv::Size(50,50));

Any hint on why this is happening?

Thanks