Tuk

can you explain exactly what you are doing?

you should be doing the following

type: /macro

click Create new macro - give it a name and choose an Icon... click OK
add the macro text (CASE SENSITIVE)
[code:1]/script AcceptGroup();
/script AcceptQuest();
/script AcceptTrade();
/script RetrieveCorpse();
/script RepopMe(); [/code:1]

Drag the icon for the macro onto your action bar

When your chars are all grouped together... share a quest (open quest log, select a quest and press the share button)

press the action button for your new macro.

note any yellow (default colour) text that is shown in your chat text to explain why it might have failed.