Yes, I would say there is a Gm you and a you you. For me it boils down to the Rpers. Sure I can be friends with people and have a good laugh but I have found that when I Rp with friends they tend to take advantage of that friendship. Acting like they should get special treatment because they are my friend. (It ends up reminding me of those horror stories of when people when the lottery)

It doesn't always happen but it can. Gm's have their own set of rules for each rp they host, gming becomes a volunteered job in a way. They have to keep things moving, plan out things, keep everything in line.

It is just like any business or job. You have work you and off work you. Sure you may be friends with you boss but if a project is due or a deadline is coming up, your boss is not your friend then, they're your boss.

Same goes with Rp. In Rp, they aren't your friend, they're your Gm. I wouldn't take it personally, personally. Chances are they're just doing their [i]job.[/i]

When reflecting, see if perhaps you're expecting more because they are your friend. More leeway with a post or cs, longer time to post. Etc. 

I am not saying it is you. Chances are it is just both of you. In an Rp, they're the Gm, you're the Rper. Keep the friendship outside of the Rp and neither take what happens in rp (ic or ooc) personally and you should be fine.

That or the person just turns into Douch Master when they have any semblance of power. Take your pick.