Mostly I encountered the errors when attempting to reply in the forums.  But also don´t see all the images load on the main page either.  I believe it´s CPU usage.  Perhaps if your on shared hosting then the other websites on the same server are sucking up the CPU usage. Even worse nowadays is they have virtualization webhosting software so you ´have your own server´ but it´s just a virtual server and it´s still laggy CPU wise.  I know one cheap host which limits you to 20% CPU usage and it´ll give an error page when it occurs.  It´s kinda sad facts of shared webhosting though.  I´d say if it really continues consider donations or what not and possibly get a server....another thing I´ll pm you about.