I have windows 7 64 bit and after about 30 min or less the windows says my internet conection is limited and I can nto download. I conect threw a linksys wmp600n to the internet.
bittorrent does not cause this problem and it only happens when tixati is in use I use the latest ver.

The simple thing is go to the support page and follow the optimize page. http://support.tixati.com/Optimizing_Tixati  . You can start by just going to tixati and clicking bandwidth, then check off auto limit. That said auto limit is not ideal because it needs to have the ratio set. Set that for the ratio of your advertised connection speed so 10Mb down and 1Mb up is a ratio of 10. To find the ratio setting click details under the auto limit check mark. Also this works better/worse for different connections I.E. DSL

the error message " internet conection is limited" indicates you have network issues.  Can Tixati cause it? I am not sure but don't think so. Routers can be fickle. When I had my old USrobotics router, I would have to reboot it every 8 hours when running torrents. It couldn't handle the traffic. When i called support, they suggested their router was just fine but i needed to use a cisco router to handle torrents.

later i changed to a d-link "N" router with 1 Gb/s swtching. It was much better but after a year or so started acting up.

I found in interesting linksys/cisco router designed for small office use, an RV082. It is just 100 mb/s but it can handle torrents. These can often be found used on ebay for under $50. They have been replaced by a new 1 gb/s model, but while that would help within the local network, 100 mb/s is 50 times my ISP ul limit.

I have found that "internet connection is limited" is usually related to some external network issues. Maybe a switch, router and/or modem needs to be rebooted.

Most home use wifi routers/switches struggle with the traffic torrents produce.