Employees get offended any time new/existing rules enforced?

I took leadership of an org. that did not have a leader for 2 yrs & the previous leader was not hands-on so the inmates ran the asylum. Employees got into some bad habits as you can imagine. I'm trying to get the level of professionalism up. However, everytime I remind someone of rules they need to be following (new or old) they get "offended" & run to my boss hysterical! I bend over backwards to be polite, I always use "we need to..." not "you need to..." and i always use language like.. "don't forget we can't...." instead of "didn't I tell you not to...." etc. I only get tough when they try to defy or make excuses. I have worked hard to not just be the new Sheriff in town - but balancing by boosting morale and recognition, even to try to make the working evironment more fun! So far my boss has not "faulted" me, I guess he understands this is just the fall-out of change but I'm curious if this normal and for how long. Anybody have any advice? Have you seen this before? Thanks!