This is a fairly new issue for me, but recently, when starting Tixati, Microsoft Security Essentials causes Tixati some serious issues. At first, I just thought tixati was having a hard time with the large number of torrents when starting, but I checked the resource monitor and saw that msmpeng.exe is doing a massive amount of reads for the first few minutes of tixati running (though the MSE UI shows that it is doing nothing.) The result is that the tixati window either lags severely when trying to interact in any way, or it starts reporting that it is not responding (though in the latter case, it reverts to a working state after a few moments.) As soon as the reads stop, so does the lag.

This has nothing to do with windows startup, as I do not have tixati running at start. I suspect that this is a problem with MSE, not tixati, but if anyone can shine some light on this issue, that would be great. I'm guessing MSE just got an update that makes it do really aggressive scanning of some kind on the type of file access that tixati does on start.

I had that problem, more easily described as tixati being slow and super slow moving files. Right clicks were very delayed. Although I tried many things that worked, I have the simplest one. In the future I will re-use this on a regular basis.

It is very simple if you are not adding programs frequently. I used windows restore and went back along time. For me the time I choose was 9 months or so, last time I added a program. Then let windows and all the other programs previously installed update after the restore.
That got rid of a hundred of windows updates (and other associated programs like flash and java) and replaced them with one that was current and had most bugs worked out. The problem with having all of the updates is they have bugs, they get sorted out in the next update etc. There ends up being a ton of bad, yet corrected code. If you dump all that and get one update half the crud won't be there. Instead of ten changes to fix something there will only be one change. Nine less things to go wrong.

Other than to say; this has worked really well several times for me and is likely just good windows habit. If you need sometime less dramatic I can tell you some other things that helped but did not solve things completely or as well.

I too have just started experiencing this. I shut off real time protection in MSE, and Tixati is working fine again. They must have had a recent update to cause this issue.

Try to add tixati.exe to MSE's process exception list. If that doesn't help, add default download location as folder exception too.