I use RXQUEUE to send messages between processes and discovered that messages appear to wrap onto themselves (or otherwise be corrupted) if they are longer than about 3,816 characters.
The sample program creates a queue, creates a message, queues it, pulls it, and compares it to the original. It increases the message length until a discrepancy is found then displays the corrupted message's length and the corrupted message itself.
Thank you! -Mark