That's not what Microsoft says:
http://support.microsoft.com/kb/2458544
"Are there any risks to using EMET?
The security mitigation technologies that EMET uses carry an application compatibility risk with them. Some applications rely on exactly the behavior that the mitigations block. It is important to thoroughly test EMET on all target computers by using test scenarios before you deploy EMET in a production environment. If you encounter a problem with a specific mitigation, you can individually enable and disable the specific mitigations. For more information, refer to the user's guide that is installed with EMET. "
http://support.microsoft.com/kb/2458544
"ISV Tasks
ISVs should link with Microsoft Linker version 8.00.50727.161 (the first version to support ASLR) or later.
ISVs should link with the /DYNAMICBASE linker switch, unless using Microsoft Linker version 10.0 or later which enables /DYNAMICBASE by default.
ISVs should test their application on Windows Vista and later
and note and fix failures due to ASLR."
Edit: certainly AMD should make their drivers ASLR-safe, but flipping the switch to make all programs use DEP and ASLR may still result in programs crashing. If it was 100% safe, MS would have changed the default setting to ON in Vista or 7.