Criteria for displaying iPhone template

What are the Postnote template criteria for displaying the iPhone template on an iPhone ?
My site (http://www.fairwater.nl) was displayed correctly in the past on an iPhone but after several updates of the template, my site is displayed in 'normal' mode on an iPhone. Can't check this with other handheld devices.
Any help is appreciated.

Best,
Gerrit

PS. Attached is the current params.ini

Hi

I've checked it on my phone and site looks ok. The iPhone mode is working for me.