.22 Semi-Auto malfunction question

[rgs1975]

I have a Weatherby XXII semi-auto, box magazine fed, .22LR rifle. Yesterday at the range I noticed some weird behavior. The rifle was self activating it's safety when being fired, sometimes. I'd say about 10% of the time I'd fire, feel the recoil (what little there is) and then go to pull the trigger again only to find zero trigger movement. Each time this happened I looked and the safety was on safe. It's a slide switch safety located on the top of the stock right behind the reciever, much like many shotguns. I've no clue as to why this happens. Any ideas?