It just seems to be random and doesnt happen conssisteently from key to key. OVERALL : I am pleased with the product so far but havent even had it for 24 hours yet. Wade into the sea in them and dont need to change later. Unlike other Crocs, I was not able to wear these for any prolong period of time. If you are on the fence about what size to buy, the standard or the queen, go with the standard for the standard size fits most peoples brick. but I chose not to! - No bag or clip to keep the cable when not in use I ordered this product and attached the little transmitter to the back of my phone. The only issue I had is one that most other chargers haven?t addressed either. For now, it is great for holding diapers and wipes, infant clothes, receiving blankets.