I'm assuming that's an ADS stream, and just like you I'm not sure how to exclude a stream from being scanned. (Of course you could exclude the directories involved or something like that).
It is strange that the problem has only started really occuring since the other server was restarted. Is there a core Windows issue with slowness of access to the other server or something similar that could be causing the problem - eg perhaps Windows hasn't reconnected the share properly or something equally as weird?
Sorry I can't really be of much help.
Which version of the McAFee Virus Scan Enterprise are you using currently and what patch is it on ?
Sorry should have included in OP
VSE 8.5 Patch 8.
Leaving out directories is not possible as all directories need to be accessible to both platforms.
Strangly the problem seems to have gone away. No entries in the OAS log since around 5pm yesterday and processor activity is back to normal.
Will have to look the next time we restart to see if the problem comes back.