Artifacts during iChat screen sharing

[orvn]

I'm trying to screen share with someone in iChat and I'm getting a screen full of artifacts.

We both tried rebooting our machines.

We're both running 10.7.0 Lion and iChat 6, build 925 (latest at the time of writing this).

For the first second or so after establishing a connection, I can see the other party's entire desktop. Then the artifacts appear suddenly and cover the screen almost instantaneously.

Below is a screenshot of the issue.

When I share my screen, it works perfectly.
When she shares her screen with someone else, the other party also sees the artifacts.

We both have good internet connections. Test packets ping quickly, download speeds are 10 & 24 Mbit, uploads are 0.8 & 2 Mbit

Anyone know how to remedy this?

(cropped this image so it fits in to the thread without stretching the div)

 

[orvn]

After extensive (and I do mean quite thorough) trail/error testing I have identified the issue.

It appears to occur when certain applications (in this case Excel 2011) are open AND bandwidth is limited on the machine that is uploading/sharing the screen.

Close open apps and restart iChat each time to determine which application is causing the conflict. Also, temporarily changing the router's wifi channel (therby knocking off other devices) resolved the issue by increasing available bandwidth.