We assessed the effects of network latency and jitter on a cooperative tele-operation task in a collaborative virtual environment. Two remote partners worked together to manipulate shared virtual objects over a network. The task was to minimize the time to transfer a ring through one of four paths with the least number of collisions. The performance of human subjects was measured and analyzed quantitatively as a function of network latency: 10 and 200 msec delyas with and without jitter. Jitter had the greatest impact on coordination performance when the latency was high and the task was difficult. These results are discussed in light of current and future CVE tasks.