[Haskell] Haskell profiler

[Srinivas Nedunuri]

Could someone tell me what the expected accuracy of the Haskell profiler is? 
I get quite widely varying results for the amount of time spent on a given 
function across different runs (eg one random example, from 1.5% to 10%). I 
even upped the size of the dataset in an attempt to increase the accuracy. 
Also a related q: why doesnt't the time spent in putStr show up?

cheers