File Sharing Violation In SQL Server Mobile Edition

Hi,
I am facing a wierd problem working with SQL Server Mobile edition database. The code works fine for some time and then it suddenly starts throwing "There is a file sharing violation. A different process might be using the file."
I am disposing and closing the connection after each operation.
Please find the function code below which is being used for any database operation.

SqlCeConnection sqlCon = null;
try
{
sqlCon = ConnectionFactory.getInstance().getPrimDsConnection();
sqlCon.Open();
readCmd = sqlCon.CreateCommand();
this.prepareStmtManyRows();
dataReader = this.readCmd.ExecuteReader();
IList result = this.populateManyRows();
return result;
}
catch (SqlCeException sqlEx)
{
StringBuilder builder = new StringBuilder(
@"SqlCe Error in BaseReader.executeList() - ").Append(
sqlEx.Message).Append(':').Append(sqlEx.NativeError);
Log.getInstance().log(builder.ToString());
throw new DataAccessException(sqlEx);
}
finally
{
try
{
if( null != dataReader && ( !dataReader.IsClosed ))
{
dataReader.Close();
dataReader.Dispose();
}
if( null != readCmd) readCmd.Dispose();
if( null != sqlCon) sqlCon.Close();
}
catch (System.Exception ex)
{
}
}

I have also made sure that Query Analyzer is not running on my PDA.
I have been working on this since last one week but could not find a soultion.

Thanks,
A Islam