I come out to my puter to see what cards I collected from two games I have running.

My invo says 2 but shows 3. I list the third and lose my invo....goes completely blank.

Figure it has to do with card I tried to list.

Go to market and there's a fourth card I didn't realize I received already listed....

So either Steam is going gummy right now or some genius has managed to figure out my password but is only able to sell shit for me.

I've read elsewhere that a few people are having problems with their inventory right now

I had this problem last week. ALL my items disappeared, like I have nothing. That lasted for 3 hours. It was fixed the same day.
Apparently, there was a maintenance the produced this issue for some users.