Homegroup headaches; random issues; one fix

This weekend, I configured three Win7 computers on my parents network: a Desktop PC (64 bit; hardline to wireless router), an HTPC (64 bit; wireless), and a Laptop (32 bit; wireless). At first, I encountered a lot of Homegroup headaches. I created a Homegroup on the Desktop, but both HTPC and Laptop would not join. After a lot of troubleshooting, I hardlined both the Laptop and the HTPC to the wireless router -- and both instantly connected to the Homegroup.

I then disconnected the HTPC and Laptop, re-instated their wireless connections, shared all default folders (i.e., music, pictures, documents, etc.) on each of the three computers, and began some random testing. I immediately noticed various strange issues/bugs/glitches.

1) With all three computers on, I could not change the name of a folder in the HTPC's picture folder. I confirmed that I was not trying to manipulate the Desktop's or Laptop's picture folders. I was simply using the HTPC to try to change the name of a shared folder on its own hard drive. The error message said something to the effect of: You cannot change the name of this folder as it is currently in use.

2) With the Desktop computer OFF (as noted, I created the Homegroup on this computer), I was unable to share files between the HTPC and the Laptop, even though each recognized the other on the Homegroup. As soon as I turned on the Desktop, all computers could share files. Surely the Homegroup-creating computer need not be on for files to be shared, right?

3) While using the Laptop, I entered the HTPC's video folder and opened a video; it played just fine. But, when I tried opening a different video (same file type), I received a message that the video file was currently in use elsewhere and could not open. This was a similar problem as #1, above.

4) Printer issues. The printer is connected to the Desktop computer. The HTPC sees the printer just fine, but the Laptop does not see it. When I open devices and printers on the Laptop, I get nothing but the default devices.

I wish I knew the exact language of the errors, but I am no longer at my parent's home (different state); various outstanding network issues remain unresolved. Has anyone else faced these seemingly random issues using Homegroups? Is there some troubleshooting technique I should employ? Did I set up the Homegroup incorrectly?

eyc, do you have a virus program or firewall on? To be honest I am also still discovering the Homegroups and strugling with things, but I found that disbling the firewall will allow some things to be setup (the printer thing is likely that)
Let me know your progress since I also need some help with homegroups

I thought it would be a long shot anyway :)
Let us know how it goes!