Is my window fitted correctly?

Hi,
I had new upvc double glazed windows fitted 2 years ago and have recently noticed one othe small windows has over 1cm of movement and didn't appear to be fixed to the wall with anything. I called the fitter who came round while I was out today and said he fixed the problem from the outside of the house (said he'd re-packed it?).

The window still moves so I called him up and he said it's because the foam isn't set and won't be for a couple of days due to the weather and smaller windows aren't fixed to the wall with screws, they're just foamed in.

This doesn't seem very secure to me - couldn't a burglar just cut out the foam with a sharp blade and remove the window? Is this right or am I being fed a line?

The window is 90cm x 103cm.

Thanks

Its not un common to fix windows with foam only, once it dries it'll happily hold a small window so when the fitter says smaller windows aren't fixed with screws although correct i wouldn't class a window 900mm x 1030mm as small, at 900mm wide theres plenty of room to get a drill in to fix it, its this reason windows are foamed in[/b]

Same thing happened on 2 of our windows.
Some cowboys don't put enough screws in to save time.
The initial silicon sealing holds the window in place for a bit so you don't notice.

Ours were so untidy that they left a few of the big screws behind so I added one or two and that has solved it.

Have you checked the sealing inside and out?
I bet their sealing needs re-doing now and having that done will also reduce the movement.