Trouble w/messaging & browser

[jbrock98]

1st)Sometimes when I click my messaging icon it opens up something different: usually its the last thing I've opened let's say when I go to open my messages it'll open my browser instead and it'll keep opening it then I go open my gallery then back to messages icon it'll open my gallery. I restart my phone then its fine. 2nd) sometimes my browser closes itself and closes out the tabs I had, i have to click on the icon a couple of times to get to open again cause it'll open close a couple times b4 finally opening

 

[jbrock98]

And I downloaded an app from brothersoft.com would an app outside the market be harmful? I'm not rooted either, thinking about it just worried I'm not droid savvy enough for it