Congratulation XTC46, you just exposed yourself as a huge jackass. Which part of:
"and no I never signed in from another computer...only from my pc", didn't you understand.
LET ME SPELL IT OUT FOR YOU...I never chat anywhere else other than at home, so this pretty much excludes your guess that I probably just forgot to sign out from another computer.

Secondly, I find it quite ironic how you accuse me of making "ridicilous" assumptions about being hacked, yet you're the one who moronically jumps on conclusions without knowing anything about me.
How do you know that I'm not using a firewall, anti-spy/malware tools and an antvirus program?
Currently, I'm using Zonealarm Pro (albeit it can be argued about how effective a sowftware based firewall really is), ad-aware, several other anti-spy/malware "clients" and a decent antivir program.
My browsers of choice are Opera and Mozilla, besides I'm very cautious with what I download from the internet. To be honest, I rarely download stuff but if I do, I make sure that it's from an official site.
When using the Yahoo Messenger, I never click on any links within the client, never share files with someone I don't know. Most of the time I just talk to the people who are on my buddy list.

Also, which basket case would give his password away - even if it's your friends?...yeah right, good one buddy.
"Shoulder surfing", huh? May I ask, how old are you?

The first thing I did, after this problem occured was to change my password - thanks for nothing.

So there you go, you just made a fool out of yourself but please go ahead and type more ignorant babble bullshit and let me publicly bust your ass again or just stay the **** out of my thread and let people post some constructive info here.

To everone else, thanks for the input. I am not giving details here but I've very good reasons for thinking that someone indeed tried to get into my account and read my mails.

So, what I'm asking here is, are there any known bugs/"Yahoo glitches" that occured lately within the yahoo servers, does anybody else ever had this problem before, or is it most likely that I've been hacked?

P.S.: I already scaned my system and nothing seems wrong (I'm the only one who uses my computer).
It's supposed to be very easy to hack an email account, if you know how to do it...