I am astonished by the hypocrisy on here and the total inability to see another point of view. No wonder some people (on both "sides") have problems in their day to day lives when dealing with their children's natural Mum/Step Mum. 
I am on both sides, as I have said. As the Mum, I bend over backwards to promote good contact with my DC's bio Dad. He has as much contact as he can accomodate (less than I've freely offered) and unrestricted telephone/email/text contact as well. I try to accept that most things that bug me are down to different parenting styles and I bite my tongue a lot when dealing with my ex.
As the Step Mum I am happy for us to base our maintenence payments on the family income as a whole, which means I top up my sk's child support as I am the higher earner. I treat the children just the same as my own children and I would do anything for them, the same as I would my bio kids.
However I am also big enough to see that you often can't win whatever side you are on. My sk's Mum thinks I am the devil incarnate and I genuinely don't know why. She has accused me of "inappropriate behaviour" but despite requests to clarify what exactly she means, so that we can offer reassurance, she has never said what her concerns actually are. I am pretty sure if she was a member here she would be slating me as she really does dislike me and calls me (to her kids) "the b*h your father has married." That doesn't mean all first wives or whatever the correct term is behave this way, and I'm sure that most don't however SOME do.
It's the same with step Mums - you get some good, some bad and some indifferent. My dc's step Mum is indifferent most if the time. She got my ex to reduce his child support payments because he was "paying too much" which is something I don't understand, but ultimately she is not a bad person.
Why is it so hard for people to grasp that the Mums and Step Mums who are getting along great and have it all figured out aren't posting here because they don't need any advice and support? The step Mums AND the Mum's posting make up such a tiny minority of the total Mums and Step Mums in the country that it is ridiculous to point to these boards as shining examples of who is at fault when things go bad and to blame one side or the other.
The fact is some people are just not nice - they might end up being Mums, step Mums or both and will still be not nice. Most people posting here are rec
ognising there are issues and trying to get support to solve them and/or are having a rant so they can get things off their chest they wouldn't want to say to the person in question. That would generally make them nice people, or at least people who are trying to be better.
Is it REALLY that hard to see that?