I use firefox for years, and last year, I started to use google calendar to arrange my daily schedule. Recently, I found that when using firefox to browse google calendar, even do nothing, just open it and open the task manager to check its memory usage, the memory usage is growing, about 10~50K per second, I usually open the google calendar for all day, and after close the google calendar tab, the memory usage is stop growing. I also tested this on google chrome, but it won't.

OS : Windows XP SP3 CHT Firefox : version 28.0 and 30.0 have the same problem.