Reading the excellent guide 'MIDP 2.0: Tutorial On Signed MIDlets' I came away with the notion that buying a code signing certificate from Verisign and signing your application would allow your MIDlet to execute in the 'Trusted Third Party' domain.
This would appear to not be the case when tested with the 6170,7610 and 6230 (the application is untrusted).
Following this up I have two questions:
Do any Nokia handsets trust the application if it's signed by a developer's code signing certificate?
And is there any other way to become a trusted application without going down the Java Verified route (as only a handful of handsets have the certificate)?