Problem editing and splitting videos in Movie Maker 2012

Lately, Ive had an issue in Movie Maker where splitting videos deletes a large portion of the video or sometimes leaves a gap of white space in between one clip and the next when I right click and hit split, ive also tried splitting it through the Edit menu, but it does the same thing. For example, I have a video that is about 10 minutes long, and I was going through splitting the videos into little segments to type in captions and subtitles, and I got to about the 8 minute mark, and then when I tried to split the next video, the length went from 10 minutes to 1 minute long. I usually undo the split right after that to preserve the editing ive already done. This happens to almost every single video Ive done recently, and the only way I could finish was to constantly delete and re-add in the videos that were messed up, only to have it happen again after I split the video another few times.