Was trying to export a site in WSS3.0 using the following command:
stsadm.exe -o export -url http://blah/blah -filename BlahBackup -includeusersecurity
Which promptly spit this out:
Operation aborted (Exception from HRESULT: 0x80004004 (E_ABORT))
This seems to be a fairly generic error, I was finding causes ranging from SQL Log file size to threading conflicts. The most common solution was to shrink the SQL log size of the content database of the site you're exporting. In my case this wasn't the cause of the error, instead what solved it was running the above command as a user who has DB_owner permissions to the content database.