IMO you need to move away from Proboards ASAP and host the forums yourself - Proboards can delete your community without notice or consequence, and I've seen this happen before with other free forum providers when a forum gets too active.
Look at options such as MyBB or SMF if you're on a budget - they're free - or vbulletin if you want to go the whole hog.
Either way, I strongly recommend no serious business ever host a major part of their site with a free hosting provider, because all it offers is risk of loss of data. You need to have full control on that IMO.
Feel free to ask in Platinax if you need more help with forums, not least implementing anti-spam measures.