iChat "Share My Screen" grayed out

I'm experiencing an issue with the "Share my screen" feature on iChat. I've been able to successfully establish a connection with two other people in both directions (letting them control my screen, and controlling their screens). However, I have some issues connecting to my dad's (whom, of course, would be the most helpful to have the feature with for support/troubleshooting).

In the past, we always use Skype to share his screen, but as you might know, I can't control it which is kind of a pain. Every time I try to teach him to do some thing, we usually ended up by yelling each other which is frustrating. Thankfully, with the appearance of iCloud, we can have our own @me.com (I know we can use AIM, but my dad just doesn't want a new account).

Basically, in iChat the option to request control of his screen is grayed out when I attempt to connect to him. On his end, his option to share his screen is grayed out. Interestingly, my option to share my screen with him is available and he can request to control of my screen. We backed to our Skype and I tried to go to iChat preferences and System Preferences to find out what the problem is, but all the options are matched.

He has an early 2011 13" MacBook Pro. I have a mid 2010 13" MBP and my uncle has a late 2011 21" iMac. Both our Macs can't ask my dad to share his screen, so I believe is his problem. They are all running on Mac OS 10.7.2.

If you have any solution or suggestion, please HELP!

Thanks!

Jerry