I've never had problems with phpbb. Even the newer ones. All our squad forums are phpbb. Don't use the one from cpanel, download it directly from phpbb.com. You shout not have any problems with installing. Also follow Liquids suggestions. I think this is my second choise for forums.. The acp needs some work though.. Some needed things are missing or just aren't advanced enough..
Invision board is great.. but waht sucks about it is the inability to custom skin it. I mean, make your OWN skin, not download one. It takes a long time.. That's what I didn't like about it. Also when you get the skin untraing it from the server with invision etc etc what a mess sometimes
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XMB is one it way to be good, but I could code it so it's not that great. I've fixed so many bugs with my xmb forum at phphq.net it's not funny.. It needs alot of work. There are far to many security issues with it.
vbulletin is still the best.. but $180 is still expensive.. Like G.I Goe said, if you got a big community, vb is the way to go.