Perfect! Thanks! Just replaced the acronym with span, so it's working allright now.
oTag = "[acr=*"
c1Tag = "*]"
c2Tag = "[/acr]"
oTag = "[acr="""
c1Tag = """]"
c2Tag = "[/acr]"
This works fine, as long as the same post does not contain any instances of [url=
...
So, I'll stick to [acr=* *] as syntax for the time being.<