list number messes with indents

I have a list that looks like so

c) Item first
d) Item second
e) Item third

because it has continued the numbering from the
previous list in a previous section. All of these are
the same style (which is called List Alpha if it matters).

Fine. So I right click and choose "Restart at a" and then I get this.

a) Item first
b) Item second
c) Item third

Now I can manually correct the indent. But I have this situation
about sixty times in my document. I'd rather not have to manually
restore the indenting every <expletive> time.

What's going wrong here? How can I get it to restart that list
without mangling the indenting?
Socks