Does anyone else's baby do this?

My DD is 4months old and is very easliy upset and gets especially worked up at other people's houses. For instance at Mothers Group at one of the girls places this morning - she woke up from a super 2 hour morning sleep, had a feed and we were there within abotu 30 mins of her waking. But after 10 minutes of playing on the floor she cracks it and starts crying - really crying as though she has not slept for 3 days or something. She does it every week and I'm starting to think she is ver unsociable! She is very hard to settle until I leave and take her home. She did the same thing at my in-laws the other weekend and it is driving me nuts.
Short of staying home all day everyday I don't know what to do!