checo,
those mounts are just fine.
its about what you bolt the mount to...
they are usually mounted to the facia boards of the roof, at the apex.
depending on the age of your house, and the climate you live in; these facia boards could only provide as much support as thick cardboard.
to try for the most secure installation:
first make sure the facia boards are not rotted, or infested.
then get some 10d-16d galvanized nails, and reinforce the facia boards where they are nailed together.
a few fresh nails can tighten everything up nicely.
now, dont bother with lag bolts or big wood screws; drill holes all the way through the facia boards and use 5/16" or 3/8" bolts (whichever will fit the holes of the mount).
use fender washers on the backside, and regular flat washers on the mount side.
use nylock nuts (nuts with a nylon insert in them to prevent vibrating loose),
or at the very least, lock washers.
tighten everything up nicely, and you will have a mount that will tear the side of your house off before it will fail.
oh yeah, one thing i have done in the past, when i wanted the bottom (wider) eve mount to be further down from the top one than the pitch of my roof would allow; i ran a 10' piece of unistrut across the facia boards and bolted it in place.
then i bolted the bottom mount to the unistrut.
there's always a way!
good luck,
LC