I don't know what you mean by, "and its up to date" ashquick.exe runs a scan based on the avast signatures which are automatically updated or if you have changed that then you need to ensure it is up to date.
The ashquick.exe doesn't have settings like an on-demand scan it is the most thorough of the avast scans as it scans everything.
Check this for more information on this work around -
HOWTO: Scheduled Automatic Scans avast! Home Version!The major disadvantage with the task scheduler trick of using ashquick.exe is, it will scan every file of the hdd, partition, folder or file that you set it to scan; even those files not considered a potential threat, this can take a long time. It is possible to add certain folders to the exclusions list for say your media files, etc. This could leave you vulnerable if that folder got infected as it wouldn't be scanned by the on-demand scanner as you have excluded it.
The Pro version gives a lot more flexibility and the scan would follow the settings and exclusions, etc. of the regular scan.