Excel Can't Multiply - AppScout Well this is a major problem for Microsoft. They released a program with a major bug that would give errors when performing simple calculations.
...for example, it divided 65,535 by 26 to get 2,520.577. Then it multiplied 26 by 2,520.577 to get... 100,000?! Over ten thousand of these simple calculations gave the wrong answer. - AppScout
For a major spreadsheet problem, this is a big problem. They need to be more aware and test this a lot better.
According to AppScout, Microsoft is aware of the problem and is working on it.