Oh, I get critical errors all the time, as well as extremely long load times, so long, that I normally have another window open and go surfing while I wait for the iboats window to load, also get a lot of posting a message and it just says "working" and it never comes up, I have to open a new window to see if my message actually posted.
It is a combination of not enough memory and to small a pipeline going into the server, it almost reminds me of when I ran my weather server on a DSL line, just does not work well if you get more than one person accessing it.
The critical errors are normally due to the fact the server can't write to the database fast enough. Long load times, normally means not enough bandwidth. And if the horsepower of the server is not enough, nothing is going to work right. I have been through it all before with my own servers and pipelines into those servers.