But they still come out of a wallet. Eligius they come out of the most recent block payment... Never touch a wallet but yours. Like the solo pool.
There are a whole bunch of answers regarding that.
e.g. no that pool don't always do that so are some of your coins there not as good as others?, or, no there is no value difference - if there was then bitcoin would have a major fungibilty problem, or, If you want coins for "show and tell", then you're mining at the wrong pool, but the simplest answer is the best:
It causes orphans. So no.
(solo pays to only 2 addresses, so it's the same as here at kano.is)