Matlab crashes when reading last frame of a video using mmreader( ) and read( )

I am trying to extract all the frames from a video file. I am currently using mmreader to get the video object. In order to read all the frames, I may need to know the total frames in the video.

Since vidObj.NumberOfFrames did not return the total number of frames directly, I followed the same way as suggested in Matlab reference to obtain the total frames :

vidObj = mmreader('varFrameRateFile.wmv');
lastFrame = read(vidObj, inf);
numFrames = vidObj.NumberOfFrames;

I gave in a video that has approximately >1000 total frames (*.mpg video), and Matlab crashed whenever it attempts to read the last frame with this line

lastFrame = read(vidObj, inf);

To further experiment, I estimated the total number of frames by

estimatedTotalFrames = duration * frameRate;

and then attempted to read a frame which index is close to the last frame :

frame = read(vidObj, estimatedTotalFrames  * 0.9);

as expected, Matlab crashed as well :(

Does anyone know why did this happen?

I am using Matlab R2010a, in Windows 7 (32-bit) and I have K-lite Mega Version installed. Thanks in advance!