I just ran into an issue with my server at work when trying to save a page with a pretty large "complex" table ([[table]]…[[row]]..[[cell]]…[[/cell]]…[[/row]]…[[/table]]). If I reduce the size of the table, I can eventually get the page to save.
It seems like the the parser can't handle that amount of "wiki syntax" at once. I have pages with a lot more characters, but not as much wiki markup.
On the Pro site a similar error was reported and fixed (http://pro.wikidot.com/ticket:241)
Can you share what the fix was so I can try it on my server?