Latley my computer has been so stuffty with games that all the graphics settings on the games i play have to be set to the lowest low.
recently i set the graphics settings in tf2 all to low and now whenever i join a server after 30 seconds of playing it kicks me and this appears.

I googled it and it seems that when you have your settings on low like this you are able to see through walls and this is not the case for me.
How do i keep playing tf2 on low graphics without this stuff happening? Do i just need to buy a not stuffty computer? i can't afford that!!