bahahahahaha. This will make more sense to people with programming experience
stufftosend = 'text='+(text)+'&p='+(postnumber)+'&stuff='+(morestuff)...
). It interpreted that as a new value (so for example if you typed "this & that", it would think " that" is a new variable (in addition to text, p, and stuff). So that's why the text was disappearing.
The first thing I did was figure out how to replace + with the HTML equivalent +
Of course the problem now was the + was causing the same problem as other ampersands, it deleted the remainder of the post. Since &'s html ascii is just &
, it's a recursive problem. So there was no way to possibly escape the &. So instead, I replace & with "sometext" and then when displaying the text in the topic, use php to revert "sometext" to &
Anyways, the point is, + and & no longer destroy posts or disappear. Try posting a post with them and quickediting it twice to find out exactly what "sometext" is