Dreambeast: I think it is that you had a big lag, it happens sometimes something like 20~30 secs lag, you think that you have moved but a massive lag waves and you lose the game. As you can see in this topic, chesscube lag just takes 2 secs of your lag, viewtopic.php?f=12&t=35
I usually sense this happens more often if you play without refreshing your browser in a long period of time, around 80+ mins(even though it varies with each pc, if they have a lot of files in the temporary folder, cookies the RAM you got and so on.), I would say that it goes ok for the first hour or so, it also depends on your memory RAM and so. I would recommend you to close the browser and reopen it when you see this kind of things happen. Chesscube, in mozilla or in google chrome or in internet explorer, it takes a lot of memory which as you can see will make your pc slower. Thus, it increases the chances to get a massive lag wave, which has nothing to do with your connection or with chesscube server or with your oponent connection but it has to do with your pc. It helps erasing cookies and so on.
It is adviseable to not play people that have red ping specially in bullet games.
I hope this helps a bit to your problem.