If cell A contains a string and cell B references cell A.  When reading the value of cell B, the result will be
"0.0" instead of the value of cell A.

With the attached test case, I ran the following code:
spreadsheet = Excelx.new('formula_string_error.xlsx')
spreadsheet.default_sheet = 'sheet1'
p "A: #{spreadsheet.cell(1, 1)}"
p "B: #{spreadsheet.cell(2, 1)}"

with the following results
"A: TestString"
"B: 0.0"

where the expected result is
"A: TestString"
"B: TestString"

Date: 2011-02-25 18:04
Sender: Robert Yu

I had a similar problem in an .xlsx file a formula
was referencing another string cell but it would
return a float value "0.0".  My work-around was to
convert from .xlsx to .ods, which seemed to work fine.