Battery related problem

I got aspire one AOA150-1813 just a few days ago. I wonder if I should worry about the following problems:

1. When the harddrive is being read, the LCD screen will flicker a little. Although it is not serious, but it is not a good sign.
2. I open a webpage and before it is completely downloaded, I open another one on a new tab (IE 7) , then one of the working webpage will become double vision. It remains so until I refresh it.

All these problems are gone when I use AC cable. So I guess there are some defects on the battery power. They are tolerable if it would not get worse. Should I do something about it? Anyone has the same problems?

Thanks in advance