hi MxM,
Your name would imply to some that your a MX Monitor user, and if this is happening with your Moni running its called a 0 of 0 Hack, and unfortunately Leechammer is the only upload manager that can fight it off.
The 0 of 0 hack allows users to fake Moni into believing there are files shared and allows them to get into your Que, even with Moni running.
There are two possible ways for someone to 'Jump' your que.
One is a built in feature of WinMX, it allows auto uploads for files that are under 33k. There is no way around this and these files are usually done very quickly.
The only other possibility would be a glitch that to my knowledge no one has any real control of, that would be the small file jump, then quickly que for larger files and sometimes it will auto start some of those larger files..
Hope this helps ya some to understand what your seeing better..