If one performs an mathematical operation on a datasets with units all units will be stripped off when the unit manager is set to none.
When the unit manager is enabled, all computations take account of the units involved; e.g. when you have a signal with unit V and you multiply it with a signal with unit A, you get a signal with unit V A that can be converted to W using the Unit operator.
Depending on the function, it may not make sense to apply it to an arbitrary physical value. For example the Sin() function can only be applied to angles. To synthesize a sine wave based on a time series (with unit convertible to s) one can write:
Dim t = (500, 0, 10 ms)
Dim y = 4.2 V * Sin(2 Pi * t * 1.2 Hz)
The automatic determination of units can be a powerful tool to spot physically absurd calculations as adding voltages and currents.
To get rid of a unit one can use the Value operator.
There is no way to get the faulty behavior of unit management in FlexPro 8.