I think I found the answer, looking on a different discussion board.
Please reference Microsoft Knowledge Base Article 310264
If you want to save the web click trip, keep reading.
Hope this helps, it worked for me.
This article was previously published under Q310264
Moderate: Requires basic macro, coding, and interoperability skills.
This article applies only to a Microsoft Access database (.mdb).
SYMPTOMS
When you view an object in PivotTable or in PivotChart view, the data in a decimal field is truncated after the decimal point.
RESOLUTION
Use a data type such as Currency, Double, or Single that supports decimal places.
-or-
Create a query that uses a data-type conversion function, such as CCur, CDbl, or CSng, to convert the decimal field to a different data type. Then, view the query in PivotTable or in PivotChart view instead of the table.
STATUS
Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article.
MORE INFORMATION
The Currency data type most closely matches the behavior of the Decimal data type, as far as internal storage. Both the Currency and the Decimal data types are scaled integer data types. However, the Currency data type is limited to 4 places to the right of the decimal point whereas the Decimal data type supports up to 28 places to the right of the decimal point. If you must store 4 or fewer digits to the right of the decimal point, use the Currency data type.
The Double and Single data types support decimal storage, but both are floating-point data types. Because decimal fractions do not always have exact binary equivalents, using a floating-point data type can result in rounding errors. Use these data types only if you must store more than 4 digits to the right of the decimal point.
Steps to Reproduce the Behavior
Open the sample database Northwind.mdb.
Create a new table in Design view.
Add the following fields to the table: Table: Table1
----------------------------
Field Name: ID
Data Type: AutoNumber
Indexed: Yes (No Duplicates)
Field Name: Amount
Data Type: Number
Field Size: Decimal
Precision: 10
Scale: 4
Table Properties: Table1
------------------------
PrimaryKey: ID
Save the table as Table1.
On the View menu, click Datasheet View.
Add the following records to the table:ID Amount
1 34223.2345
2 234325.9234
3 92452.494
4 3467.3469
On the View menu, click PivotTable View.
Drag the Amount field from the PivotTable field list to the Drop Totals or Detail Fields Here area.
Note that all digits after the decimal point have been truncated, and that the data is displayed as an integer value.