Sqlite opening error "Unable to open database"

In my app, I use a calendar control to store the information date-wise.

Calendar Control's Link: http://blog.webscale.co.in/?p=244

For example, the current selected month is October 2010. Now if I switch back to April 2010 and try to comeback to October 2010 & access data from calendar that I stored in the month of October then I get the Error that says:

Sqlite opening Error : unable to open database file

It works fine without switching between months.

The basic troubles开发者_StackOverflowhooting and checks which I have already done are:

1. I have made changes to database file permission and containing directory's permission but it didn't help me.

2. Database file path is also proper and database is not empty.

What could be going wrong?

I got the answer; I opened the database but wasn't closing it and multiple instances of database were conflicting and causing the database to be locked.