Okay, while I agree with the above responses about having a good attitude, there's a flip side to this scenario. If the employer is doing something illegal, and blaming you for something you did not do, cutting your hours and siting the incident for doing so, that's wrong, and there are labor practices in place that protect you as an employee.
Unfortunately with the economy as it is, the employers have gotten pretty bold about not playing fair in the job market. It's kinda like we're at their mercy sort of situation....and they know it. They know there are 100+ people willing to take your job, minimum wage or not. Unfortunately it gives the employer more power than they are allowed these days.
However, You have rights as an employee, and it would be good to call the labor board and find out what they are. Not to start anything, but to educate yourself just what your rights are. I guarantee your employer knows when their bending the rules, and think your too scared to upset the apple cart for anything. In fact their counting on it.
Working for someone is a 2 way street. You give 150+% and work hard. Go out of your way to do things they don't even ask you to do, etc. If your doing everything you can to do a good job, and still being treated like the red headed stepchild, and they won't tell you what's up.....then you need to find out just what your rights are. You can call the Labor Board, and talk to someone about what's happening, and they can tell you if it's right or wrong. You can file a complaint with them, if your fired erroneously. On the other hand, the employer should be fair and honest with you if your not meeting company expectations. Not give you the silent treatment, or ignore you when there's clearly a problem. Also, if you are laid off or fired, be careful of the reason, and get it in writing. In fact, ask for it. When you go to file for unemployment, it will make a hugh difference weather you get unemployment benefits or not. If the employer refuses to give you notice in writing, that will go a long way of showing their un-cooperation, and you probably have a good case for benefits. It's tough out there, but you have no reason to be treated wrongfully if your doing your job to the best of your ability.
Standing over you with a clock watch while your taking your break borders on harassment.