I've had 8.6 installed for several days now, and many applications crash with an "Error Type -3". Internet Explorer 4.5 and Word 98 seem to be most affected (crash on program launch, crash while running), although I've also noticed it with Adobe GoLive 4.0. I believe that these programs all use some sort of MS shared libraries, which might be the culprit.
Basically, the programs I've listed are so unstable as to be unusable. Just wondering if anyone else has noticed this.