Exactly... I just started to have the same problem. My N900 would be fully charged when I went to sleep and by the time I woke up the battery was all gone. I noticed that sometimes I have the same process listed many times, and if I close it just restarts... Killing the process seems to solve it temporarily, but not completly!

The process or processes that are eating up my battery/memory and cpu are related to the browser/internet.