Not sure only to speculate that your cursor (Now time) is on that spot. However, rather than drag the clip back to an earlier position, you can just cut and paste. Naturally, just click and cut the clip as usual, but then click paste special and in the dialog you can designate the specific place you want the click to be pasted.
Perhaps, if you used the Media Browser instead of the Windows Explorer, you might have more control as to where the clip is actually placed. At least that's how I do it and haven't had any problems otherwise.
Kind regards,
tecknot