Disappearing players.

Over the last week or so i have been experiencing a new bug, During some freeburn challenges the connection between 2 players seems to be unsynchronized, this has happened to me on three occasions now.
Whilst doing challenges the players icon appears to be at the last challenge location seeming stationary, even though the player is still near you and doing the challenge, it doesn't show up any score so it looks like they are not participating in the challenge, there car is still in the game and appears to be normal with there gamertag above it, you can still make contact with it but not take it down, the viop is still working, the corresponding player sees the same with your car and sees no stats for the other player in the challenge. This seems to have started since the release of 1.7 and only seems to occur
during online freeburn challenges.
I'm trying to find out if this is a widespread problem and if it is just specific to the 360, I have posted a bug on bugzilla (332), so if anyone else has had the same problem could you leave a few details here, thanks.