I setup Adempiere Virtual Appliance for Virtualbox under arch linux today, just out of curiosity: http://www.adempiere.com/index.php/ADempiere_Virtual_Appliance_Install#Latest_Version
Despite the very good installation manual, there were three things which bugged me, but could be solved fast:
Virtualbox wont boot the VA when the module: vboxnetflt is not loaded (at my place i never needed it for windows)
Afterwards, the system still wont boot, you have to check the Virtualbox Setting at System -> Motherboard -> „Enable IO Apic“, which has to be checked
After you installed adempiere in the VA (the manual tells you how to do that), you cannot login into the system, at least i couldnt, cause there was no valid user given in the tutorial. However, after connecting to the host via: http://adempierehost.com:8080 use
as user/pw combination.