Cell animation stop fraction must be greater than start fraction

I m using Animation in table view cell...Animation is working fine when cell is totally visible.if any cell is partially visible at that time due to Animation my app is getting crashed at the line [_Mytableviewobject endUpdates];

Crash Log=Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Cell animation stop fraction must be greater than start fraction'

code section:

-(void)sectionHeaderView:(SectionHeaderView*)sectionHeaderView sectionOpened:(NSInteger)sectionOpened
{
     //ENSLog(self, _cmd);
    [_caseTable reloadData];
    NSInteger countOfRowsToInsert = 1;
    SectionInfo *sectionInfo = [self.sectionInfoArray objectAtIndex:sectionOpened];
    sectionInfo.open = YES;


    NSMutableArray *indexPathsToInsert = [[[NSMutableArray alloc] init] autorelease];
    for (NSInteger i = 0; i < countOfRowsToInsert; i++) 
    {
        [indexPathsToInsert addObject:[NSIndexPath indexPathForRow:i inSection:sectionOpened]];
    }

    NSMutableArray *indexPathsToDelete = [[[NSMutableArray alloc] init] autorelease];
    NSInteger previousOpenSectionIndex = self.openSectionIndex;
    if (previousOpenSectionIndex != NSNotFound)
    {
        SectionInfo *previousOpenSection = [self.sectionInfoArray objectAtIndex:previousOpenSectionIndex];
        previousOpenSection.open = NO;
        [previousOpenSection.headerView toggleOpenWithUserAction:NO];
        NSInteger countOfRowsToDelete = 1;
        for (NSInteger i = 0; i < countOfRowsToDelete; i++)
        {
            [indexPathsToDelete addObject:[NSIndexPath indexPathForRow:i inSection:previousOpenSectionIndex]];
        }
    }

    // Style the animation so that there's a smooth flow in either direction.
    UITableViewRowAnimation insertAnimation;
    UITableViewRowAnimation deleteAnimation;
    if (previousOpenSectionIndex == NSNotFound || sectionOpened < previousOpenSectionIndex) 
    {
        insertAnimation = UITableViewRowAnimationTop;
        deleteAnimation = UITableViewRowAnimationBottom;
    }
    else
    {
        insertAnimation = UITableViewRowAnimationTop;
        deleteAnimation = UITableViewRowAnimationTop;
    }

    // Apply the updates.
    [_caseTable beginUpdates];
    [_caseTable deleteRowsAtIndexPaths:indexPathsToDelete withRowAnimation:deleteAnimation];
    [_caseTable insertRowsAtIndexPaths:indexPathsToInsert withRowAnimation:insertAnimation];
    [_caseTable endUpdates];
    //ExNSLog(self, _cmd);

    self.openSectionIndex = sectionOpened;
    //ExNSLog(self, _cmd);

}




-(void)sectionHeaderView:(SectionHeaderView*)sectionHeaderView sectionClosed:(NSInteger)sectionClosed
{
     //ENSLog(self, _cmd);
    SectionInfo *sectionInfo = [self.sectionInfoArray objectAtIndex:sectionClosed];
    sectionInfo.open = NO;
    NSInteger countOfRowsToDelete = [_caseTable numberOfRowsInSection:sectionClosed];
    if (countOfRowsToDelete > 0)
    {
        NSMutableArray *indexPathsToDelete = [[[NSMutableArray alloc] init] autorelease];
        for (NSInteger i = 0; i < countOfRowsToDelete; i++) 
        {
            [indexPathsToDelete addObject:[NSIndexPath indexPathForRow:i inSection:sectionClosed]];
        }
        [_caseTable deleteRowsAtIndexPaths:indexPathsToDelete withRowAnimation:UITableViewRowAnimationTop];
    }
    self.openSectionIndex = NSNotFound;
     //ExNSLog(self, _cmd);
}