As you can see from this list, Reader X has only been updated 3 times since its release:
Possibly, there's something wrong with your installation that prevents the updates from taking place. Try installing them manually (in order!).
If you want to know why, you should ask Adobe. This is a user to user forum.
First of all, there's no problem with the updates. I load one, and another comes along, I load it and another comes along. I have had them come twice in one day and on two occasions twice in a row, that is I had to add an update to the update I had just updated before the thing was finished.
As for complain to adobe, I would love to. Which Adobe. look at the list and there is an Adobe this, Adobe that, adobe othe and adobe another followed by dobe yet another not to be done before there is an adobe this, that and another. Which is the real adobe???
I tried Googling it hoping to find some one site but they have so surrounded themslves with gobbledegook that it's near impossible for any outsider to get in. It's tougher to get into than a union!
Since I am familiar with forum usage, I had hoped to find some knowledge from these. But, here to they have themselves insulated by overlapping barriers.