for starters we don't know if the testmode had any effect on the chipset operations at all... we don't know whether the kernel module works correctly (i.e. whether it detects host mode and initiates required comm protocols - there are tons of stuff one has to do even before a client session,so it's possible we left out something) etc. - someone with usb-debugging skills (at sw and hw level) has to look into this to give a final verdict.. for me, the official "n900 doesn't support otg on hw level" statement is too vague...