If you haven't already figured it out, keep fiddling with it. I had a similar problem and read some of the stuff on Microsoft's Web site.
One thing they suggest is leaving and rejoining the Homegroup.
I have two user IDs on each of my computers and I seem to be able to see only the administrator ID in the Homegroup, but I can still access those computers through Homegroup.
Also, it seemed like only the other computers would show up in the Homegroup, then all of them including the one I was working on would show up.
I wish I could be more definitive, but keep fiddling and researching and you'll figure it out.
Right now I'm having an issue with editing and saving files between computers. There are a couple of options in Homegroup set up on how you allow files to be edited and saved. I haven't been able to find any definitive source for explaining these options. Also, since all the computers were upgraded from other OS they seem to have brought forward some of the network sharing permissions from the old OS setup.
Windows 7 is MUCH better than Vista and XP, but it will take some effort to learn about all the new features and clean up the mess that upgrading seems to have created.
Check out SyncToy 2.1 on the Microsoft site. I'm still trying to figure out how it works, but it should allow you to keep your files synched between computers if you keep copies on both your laptop and desktops.