Oh yeah, but aegis-dpkg should nkt be needed at all on a device with open kernel!
I guess it is really only a cert ossue and setting date should do the trick.

Please give us the output of
uname -a
to check if kernel is really the open one.

There is another trick necessary when replacing original system packages:
AEGIS_FIXED_ORIGIN=com.nokia.maemo dpkg ...
BUT do this only when you know what you do!