There is something strange in Portuguese version. The new error message:
Incompatible AV Software Running
avast! detected that the following program is running: Norton Antivirus
The on-access scanner module of this program and the on-access scanner of avast! CANNOT be active at the same time.
As a result, the avast! main on access scanners - Standard Shield, P2P Shield and Instant Messaging Shield - were disabled.
When I scheduled Norton Speed Disk at startup (so, before complete login) it runs as usual. Finishing the application I get the error above.
Of course, I don't have NAV (just other Norton Utilities). More strange than this: after clicking the button 'ok' of that message, all providers start normally and were well configurated!
There must be a better detection of the presence of another AV installed, specially of those -
bad ones - which have a lot of things more than the AV itself.
The simple presence os Symantec drivers and folders is a too poor detection (if avast! does only this!?)