I don't recommend people to use mojoPortal on Mono for important production sites.
I've been interested in Mono since 2004 and for 6 years I've done the extra work trying to support Mono and hoping it would become a stable web environment for mojoPortal. I'm still waiting, it hasn't happened. No web hosts will offer it because they can't support it. From time to time you might get lucky with a release of Mono and it is stable enough (ie the bugs are not critical) but it could break on the next Mono release, or a new feature in a new version of mojoPortal may reveal a new bug in Mono. I don't blame the Mono team, they are chasing a moving target with the .NET framework and will always be playing catch up. To be honest my interest in Mono is waning for this reason, it has been an elusive dream to be able to run mojoPortal reliably on Mono. Also my impression is that the Mono team is more focused on newer trends like mobile development than on ASP.NET these days. Not saying they don't care about it, just my impression is other things are higher priority.
What is really needed to reach the goal of being able to run important production sites on Mono with mojoPortal is someone who is a sharp developer, a Mono enthusiast who is comfortable on Linux and can work with the mojoPortal code on Linux using MonoDevelop to join the mojoPortal team and take charge of testing mojoPortal on Mono, finding the bugs and reporting them to the Mono team so they get fixed and Mono becomes more stable. It could happen if we had someone (or several people) dedicated to this, but I cannot do it myself, I'm spread too thin and cannot give it the amount of effort it would take. The Mono team is very responsive to good bug reports, the problem is I don't have the time to do all the testing to find bugs and make good bug reports.
So, if there is a community of people out there for whom mojoPortal Mono support is important, I challenge you to step up and help make it happen. Until then running mojoPortal on Mono will always be a "your mileage may vary" situation which is not a situation for important production sites. If you are interested in being our Mono Testing Champion or form a mojoPortal Mono Team and organize a few people to help, let me know, I would welcome your help. I will say that if it ever becomes possible to run mojoPortal reliably on Linux with Mono, then it would open the door to other opportunities like making a mojoPortal Linux appliance using SuseStudio. It could be very exciting, but I can't do it myself because I'm drinking from a firehose of exciting things already.