Sqlite Database value is automatically getting changed or deleted

I have a major issue and its very less reproducing.Below is the scenario:

1. I'm logging into app by authorizing with server by httpGet and once log in is successful I'm storing username and password value in app's sqlite DB.

2.After this if user is login second time ,app is checking if username pwd is available its not going for authorization and user is directly getting to next screen.

Issue: 3.Problem is if I'm keeping app in running state for 2 days and after that I'm starting app by clicking on icon, I'm unable to skip log in. Still I need to go with username pwd, but I have already stored them.

4. why this, as my app is already storing user credentials then how this is coming as null.

To check this scenario, I can't keep app in debugging mode with eclipse. SO please help me out to solve this issue.

Is there any tool that I can see my internal DB using phone.??