Below Might work, its from an earlier discussion thread. I also know another fix, if this doesn't correct it let me know. I will need to get some code.
Reply From: Glen Albert
Date: Sep/16/05 - 11:20 (PDT) NEW!
Re: Toolbar will not expand after
I think it happens if you quickly move the dialog when it's pinned before it
has a chance to expand. The fix involves editing the registery. You need to
close the dialog, then from the windows start menu pick Run and enter
regedit.
Expand the the registery to the following location.
HKEY_CURRENT_USER\Software\Autodesk\AutoCAD\R17.0\ACAD-5001:40 9\Profiles\<>\Dialogs
Your acad version will be different and you may be using a named profile but
you should be able to get there. You'll find a key called
AeccUiDlgNetworkCreateCmdToolWnd.
Expand this key and you'll see WindowPos. Right click on WindowPos and pick
Delete. Next time you run the network layout command it will restore it to
its default location.