I know this works, the programmer at AC says they were running into problems with the linking - I think it works this way because the codes you entered were linked because of ASSOCIATED ICD 9 CODES in ADMIN functions, but if you quick add labs and don't go to the effort of all the associated ICD-9s it won't separate them and just put them all after each lab.
He did say that a release that they are working on will address this (also working on e scrip refills and workflow). I think it is still a bit of a work in progress, but continues to get better.