Hi,

My DD is nearly 5mths old and when we travel or stay at Mum's place or in-laws' we bring the portacot with us (the one you are talking about) and they are perfectly safe. They can't tip them over especially at that age!! We also have a little bed that goes in it which DD always has in her cot at home as it makes her feel snug and supports her. Its called "my little bed" i bought it from Mothers Direct. just google it you will find it.
it's a great product. folds up into a little bag with a handle so easy to carry around !!