I am receiving spam messages from my own Gmail account, what the...!?

I am a GMail user. GMail was the first to introduce inboxes with gigabytes of space thus nearly eliminating your need to delete mails just to monitor your mailbox space. I am also a fan of their spam filter which I find very good (at least for my needs).

You see, I make it a habit to once in a while visit my spam folder just to see if I am missing some emails which GMail inadvertently marked as spam. Imagine my surprise when I found an email message sent by---ME in the spam folder! This message contain some non-sense ads! I quickly checked my sent folders and there was no log or copy of any messages that I sent to myself. I doubled check and the message indeed indicate that it was my email address as the sender

So what's happening here..?

My first thought was that somebody logged in and sent an email using my account. This was not an unlikely scenario since I read from different blogs that your email account can be easily hijacked. You can read a detailed user experience from David Airey's blog.

I googled and searched the web to find possible explanations and solutions to my problem. However, I was not lucky enough to find any. I even made a post to google groups but I am still awaiting any response. I'll update this post as soon as I get any information.