which version are you using? it might be an issue with Multiple Presence. so you might need to sign out of one device before you can sign into another if it's not working. Worth a shot at trying to see if it fixes the problem though
I've tried that. I'm using WLM 2009 on both devices. it tells me that it cannot establish a connection to the service. Like I said, I can sign out and sign back in on my desktop just fine, but on my laptop, not a chance.