test without lightboost and/or try your old monitor to narrow down the problem... check if it happens offline
did you change anything in your config when you got the new monitor (like fps_max ?)
use wired (why doesn't it work with your ethernet cable?). ppl use wireless then get surprised when their shit freezes /thread.
try fullscreen instead of noborder/windowed
try fps_max 121/241 (or 0, try toggling vsync)
try -dxlevel 81 (or 90 if you're in dx8)
try a new mouse (probably its not this but a mouse can cause the entire game to freeze as evidenced by my g400)
check if your cpu/graphics is overheating
computer specs? (are they really bad?)
for rates: the same old argument from CS where 101 > 100. in TF2 one could make the point that 67 updaterate and cmdrate is better than 66, on 66 tick. it only causes (extremely minor) problems if you use cl_interp 0 because it will set your interp too low, which is why cl_interp 0 isn't optimal. supposedly cmdrate is slightly under 66 if you set it to 66 similar to how setting fps_max 120 results in it being slightly under 120 and it displays as 119.
also the cl_lagcomp_errorcheck command has been deleted from the game.
also hi jewbagels c;