That doesn't really mean much, it can be down to a problem with the routing from virgin to the host, or the routing after virgin, that because another isp connects at a different location is missed.
I'm using voice comms of various types on a regular basis with no problems.
A quick play with a trace routing programme* shows me that the connection to the op's server appears to be fine.
Right up to the last hop, where it's losing about 10% of the ping packets (which if it's happening to voice comms i'm guessing will cause a problem).
PHP Code:
Host Name IP Address Hop Ping Time Ping Avg % Loss Pkts r/s Ping best/worst
* Unknown Host * 192.168.1.1 1 2ms 1ms 0% 78 / 78 0ms / 19ms
* Unknown Host * 10.136.xxx.x 2 9ms 100% 0 / 77
xxxx-xxxxx-a-v124.network.virginmedia.n80.4.xxx.xx 3 8ms 27ms 0% 77 / 77 8ms / 119ms
lutn-t3core-1a-ge-013-0.network.virginme62.252.64.93 4 9ms 25ms 0% 77 / 77 7ms / 168ms
pop-bb-a-so-220-0.network.virginmedia.ne213.105.175.149 5 11ms 24ms 0% 77 / 77 9ms / 107ms
* Unknown Host * 195.50.91.69 6 12ms 22ms 0% 77 / 77 8ms / 158ms
ae-32-56.ebr2.London1.Level3.net 4.68.116.190 7 75ms 28ms 0% 77 / 77 13ms / 130ms
ae-44.ebr1.NewYork1.Level3.net 4.69.137.78 8 95ms 99ms 0% 77 / 77 85ms / 208ms
ae-2.ebr1.Newark1.Level3.net 4.69.132.98 9 101ms 114ms 0% 77 / 77 83ms / 198ms
ae-11-51.car1.Newark1.Level3.net 4.68.99.5 10 92ms 111ms 0% 77 / 77 81ms / 264ms
CHOOPA-LLC.car1.Newark1.Level3.net 4.79.189.182 11 92ms 118ms 0% 77 / 77 86ms / 352ms
66.55.131.14.choopa.net 66.55.131.14 12 86ms 100ms 9% 70 / 77 84ms / 194ms
*UO Trace - it's meant to be for checking the games servers, but it works, is easy to use (for any server) and free :p