Unity 4.0.0f7 GetThreadContext failed

Hi,

We have a web player application built with Unity 4.0.0f7.

For some reasons we use LoadFromCacheOrDownload(). First, it seems that this call prints this :

starting www download: ... cached to ...

Is it possible to disable this print ? The next big problem is the GetThreadContext failed.

Why this error is thrown ?

In our case, the error appears when we are using LoadFromCacheOrDownload() or when we have a lot of Debug.Log().
For optimization reasons, we disabled our Debug.Logs.
Another "funny" thing is that it seems to crash only with computer whit Nod32 activated. Does somebody have any clue about this issue ?

Thanks a lot !