Has anyone got sensible results from an annual peak solar radiation calculation?

I've tried a complex object and also a simple hemisphere to check when I didn't believe the results.

I ran a calculation for 'Peak' solar radiation (under Solar Access Analysis) for all model objects. The results are extremely suspect as there's no difference according to orientation. The total 'Peak' radiation on the north is the same as on the south (that's total, not just diffuse).

Running 'Cumulative' solar radiation on the other hand seems to give believable results.

What's up? Would someone like to try this for themselves and see if it works properly (I tried both version 5.5 and 5.6)?

Nick