Problem solved!

I couldn`t upload my hotlap, when I was logged on with normal user, but I could upload new hotlap, when I was signed on with administration rights.

Quote from AutoPilot :

That's strange. Are you sure that those faster laps are HLVC ok?

Yes, I tried 3 different Hotlaps and none of those were uploaded.

It can`t be about that I`m Demo racer. I have uploaded one hotlap already, but I can`t upload better one.

Problem is that I can`t upload new hotlap.
First, I uploaded my hotlap, when my best was 1:15.46, but now I drived a better lap and I just can`t upload it.
Browser says: Sending request to www.lfsworld.net..., then it says: Done.
I tried 3 different hotlap files, but none did work.