Shouldn't keyservers store and provide subkeys?

[Adam Funk]

Following a recent discussion about subkeys, I decided to add a new
subkey and revoke the old one on each of my keys (one used at work,
one at home).  Then I tried to update each machine to have the new
public subkeys (using pgp.mit.edu):

work $ gpg --send-key WORKKEYID
home $ gpg --recv-key WORKKEYID
home $ gpg --send-key HOMEKEYID
work $ gpg --recv-key HOMEKEYID

In both cases, the output of "gpg -v --list-key KEYID" showed that the
new subkey had not been added.  I had to use --export and --import to
get the subkeys transferred in both directions.

Is this normal behaviour or did I do something wrong?