Same query fetching different results - sql-server

Question

I am following this article series to learn about ROLLUP and CUBE
http://beyondrelational.com/modules/2/blogs/28/posts/10471/tsql-lab-6-using-with-cube-to-generate-subtotal-and-grand-total-rows.aspx
For this query:
select
case
when grouping(CustomerName) = 1 then 'All Customers'
else CustomerName
end as CustomerName,
case
when grouping(ItemName) = 1 then 'All Items'
else ItemName
end as ItemName,
sum(quantity*pricepercase) as Amount1
from orders
group by CustomerName, ItemName
with cube
The author has result like this:
CustomerName ItemName Amount
-------------------- -------------------- ---------------------
Jacob Item 1 312.50
Jacob Item 2 480.00
Jacob All Items 792.50
Mike Item 1 75.00
Mike Item 2 44.00
Mike All Items 119.00
All Customers All Items 911.50
All Customers Item 1 387.50
All Customers Item 2 524.00
The two extra rows generated by cube are the last 2 rows. I get results like this:
CustomerName ItemName Amount
-------------------- -------------------- ---------------------
Jacob Item 1 312.50
Mike Item 1 75.00
All Customers Item 1 387.50
Jacob Item 2 480.00
Mike Item 2 44.00
All Customers Item 2 524.00
All Customers All Items 911.50
Jacob All Items 792.50
Mike All Items 119.00
The first result set looks appropriate. Why is there a difference when I run it?

Answer 1

IIRC SQL does not guarantee any order except when you explicitely have an ORDER BY in place... sometimes different SQL Server versions/patchlevels "order" differently without an ORDER BY.
I don't know whether the author produced that result using SQL Server 2005 or 2008 or 2008 R2 etc. BUT I higghly suspect that this is the reason for what you see...
IF you need a specific order in the resultset always use an explicit ORDER BYclause!