.sis file won't install - any ideas.

[TurtlePower]

Hi

have tried to self sign and install an sis file but keep getting the following error when following the following prompts

untrusted file screen - continue? Yes

then

application not compatible with phone continue anyway? Yes (i know app is s60 compatible)

finally and the nail in the provebial coffin the following error occurs

"unable to install a protected application from an untrusted supplier"

the app is unsigned and i have signed it using mobile signer - signsis

tried to use open sign beta which i have used before but it keeps erroring that the emaail is not compatible with my application file (this is at symbia signed)

any ideas on why this is occurring?

Thanks