PowerPivot does not honour the regional settings of the computer it is running. It uses the English digit grouping and decimal symbol characters, regardless what the regional setting is. The languages that have comma as a decimal symbol i.e. Turkish, German, French etc., causes the powerpivot to break.
When I import data into PowerPivot from SSAS DB that contains currency data type measures. The decimal symbol is a DOT whereas it has to be comma (because of the regional settings)
When I create a Pivot table that sums the Measure, I get error indicating incompatible data type, because it treats the measure as text (because of the digit grouping and decimal symbols)
If I try to format the PowerPivot column Text to Decimal, I get completely wrong data(because the decimal symbol means something else!)