Wow. I just saw headHUNTERZ's post. I searched the SteamID that headHUNTERZ say that you originally posted and i finally found a ban! Haha
And yea, now i agree with everything. Your nick was "Mohaned" you got banned for Eye Test Violation by SMAC and the ban invoked on 02-04-13 14:39.
And because i read that you don't know what Eye Test Violation is, i'm sure that you don't know what SMAC is too and because i always support that knowledge is power, take a look at the following links:
SMAC (SourceMod Anti-Cheat)
Eye Test Violation (Full name: Eye Angle Test Violation)
Let's start from the SteamID issue. You say that it has changed after you reinstalled the game but when you tried to join Setti servers you were still banned even with different SteamID. For me it seems like your SteamID is hasn't changed and you tried to join with your original SteamID. If you want to convince me join a server, go consol, type "status", hit enter, take a screenshot, uplead it somewhere and then post the link of the image here. And be careful. I don't want to see any fake image. After you convince me about that, we will discuss about the rest.
@ heady
I had already seen it before you reply, but i delayed to reply cause i was searching for wiki links about SMAC.