There are generally two types of standard deviation calculations, one for when your data represents a sample of the population, and one where it represents the whole population. The former divides the squared deviations by N-1 (the sample count minus 1), whereas the latter divides by N.

As pryrt points out, you can get Statistics::Basic to do both by setting UNBIAS to true, whereas Statistics::Lite gives you two separate functions. Note also that Statistics::Basic defaults to a precision of 2 decimal points - this can be changed by setting IPRES to the desired precision.

Just for fun I did a little comparison table:

 

Excel	STDEV	0.41068873	STDEVP	0.400791162
Open Office	STDEV	0.4106887305	STDEVP	0.400791162
Statistics::Lite	stddev()	0.410688730467897	stddevp()	0.400791162022762
Statistics::Basic	stddev() UNBIAS true	0.410688730467897	stddev()	0.400791162022762