Unfortunately, there is not much the court can do about these complaints, so the best thing a parent can do is try to maintain as cordial a relationship as possible with the other parent, and talk about these issues in a nonconfrontational way. It will probably be hard, and may be impossible, but it is worth a try.
Here is my favorite piece of advice to my clients who are involved in disputes with the other parent: You will sacrifice anything for your kids, right? (right) If you need shoes, and your kids need shoes, who gets the shoes? (answer 100% of the time: the kids) Sacrifices come in different forms. Your sacrifice for your kids will be to bite your tongue when you feel like criticizing the other parent. It is a real sacrifice–just like not buying something you need so your kids will have what they need.
I know, I know, much easier said than done….In sympathy, Deb