GAK. Well, I guess it you have noob programmers and a buffer overflow at 1024, it's a lot easier to truncate the messages that to actually find and fix the bugs. /me sighs. I'm obviously getting too old.
The fix is easy: break the message into two or three parts. Just remember to identify the parts, and break them at logical points, because the order of delivery is not guaranteed, so users will need a clue when, as happens (rarely, but does happen) they get the parts out of order.
According to
http://wiki.secondlife.com/wiki/Limits:
Length of a chat message and whether or not it is truncated: 1024 bytes or single-byte characters. Limit does not apply to instant messages via llInstantMessage and communication between IM and email, the limit there is 1180 bytes or single-byte characters. This is true as of 2012-08-13.
So this isn't a new change.