This is dictated by a Magus configuratiuon variable called DBC_MAXTASKS, DBCONTROL will display the current settings during its initialization (the default is 10).  The value can be easily changed using the INSTALL utility run with the CONFIG parameter. 

	U META/INSTALL CONFIG

If you enter the DBCONTROL menu, the DBC_MASTASKS (option 5) and then enter '3' for DBC_MAXTASKS, you can the current value up to a maximum of 255 (it may be 100 on earlier versions). After changing the value, you MUST restart DBCONTROL.