I know you posted this a couple days ago, but I was using Analytics at that time and did not notice any break in normal activity. If you are still having problems, maybe you should contact support - that is, if you're sure that the problem isn't just that you're not getting hits.
I think you must double check it. Make sure that you planted the right code on your site and then check the source code of your site once you're done. When you see the code on the Page Source, then worry no more cause it's already working.
If you use WordPress, chech out this video, and check, maybe you made some mistakes: www.youtube.com/watch?v=QaAgbB5wreg
Try to keep separate http text log for your site. This will allow you to check if your google analytics is working as expected.
that time possibly only you will have that problem but most people did not find any trouble, so it may be problem only with you
You should check analytics once in a day as it updates only once in a day. And if you often see this problem them you might have placed code at wrong place