When upgrading a German version of CRM 3.0 to version 4.0, a strange thing happened. All decimal, float or money fields behaved very strange.
Example: User enters a value 2. After clicking save button, the number changes to 200.00 and then immediately to 20.000.00.
Then I noticed that a decimal separator and a thousands separator were the same. Therefore I checked organization settings where everything looked fine.
The problem lied in user settings where both separators were set to dot (.)
Change must be made for each user. Set the decimal separator to comma (,).
Update the CRM database to affect all users: UPDATE UserSettingsBase SET DecimalSymbol = ','