One of the best things you can do if your machine doesn't boot Haiku, is to file a bug report here, and send them the entire boot process. You can do this via a serial cable (see Serial Debugging) or by sending pictures of each boot screen before Haiku crashes. Many computers, and especially laptops, don't have serial jacks anymore so that isn't really an option!
Press the spacbar immediately before Haiku boots and select 'safe mode options'. I usually put an 'x' (spacebar or enter) in each item, but most importantly the last item 'enable on screen debug output'.
This is what the devlopers need to see. Haiku will boot showing all the commands sent.
Before the whole process would fly by very quickly (which wasn't very useful), now each page pauses and asks you to press any key to continue. You can therefore take a picture of each screen with your digital camera, and then compress it in an archive and file a report - much like I've done here. We're also trying to build a hardware database, so you can share your experience/comment with other users.