I used to be able to import an Excel spreadsheet range into a Word document.
I recently upgraded from Office 2000 to Office 2003 and now when I try to
import from Excel, I get a conversion dialog box that says, "Select the
encoding that makes your document readable." The default is Windows, but I've
tried all options and none are readable.

The way I've been used to importing these spreadsheets (in Word 2000) is:
INSERT | FILE | Select the Excel file name |Select from the dropdown list:
SHEET1 | Enter the cell range to insert

This allowed me to insert a fully editable/formattable version of my
spreadsheet.

Can anyone help with this conversion issue?