ExcelBanter - How do I create unique pivot tables from the same data

I have a table for inventory. It has 31 rows as one per day. It has a column
for each product, about twenty or so in all.

I can create the PT without a problem.
But if I create a second PT based on the same table, even if I place it on
it's own worksheet, all the variables change on both pivot tables.

Example:

PT#1 Requires the Date as Row Headers, grouped in 10 day increments, and
certain but not all products represented in columns with various calculations.

PT#2 Requires the Date as Row Headers, grouped in 5 day increments, and
certain (different) but not all products represented in columns with various
calculations.

As soon as I set the Date group in PT#2 to 5 day increments, it changes the
10 day to 5 day as well in PT#1.

Also I may need the same field summarized via sum in the first PT but
averaged in the second. I haven't tried it yet, but if the grouping is
global...... is that going to be a problem?

All advice or reading recommendations greatly appreciated. Thanks folks.
Phil