Just a general one really..
Arranging to meet my friend whom I haven't seen for ages, she used to work with me so mentioned it to some other people I work with and they were up for seeing her too. However these people seem to always change their mind at the last min/organise things then back out, so I am not surprised to find they are not now coming.
This doesn't bother me (still going to see friend will be larded with curry), so I haven't said anything to them or made a big deal.
However does it bother you? do you speak your mind about it? I have friends who have done this in the past and I just stopped inviting them to things, again not made a big deal of it.