PMs Not Sending

I just typed up a very long pm and it didn't send! I went straight to my 'outbox' to check it out and it wasn't there. Another member on my board has said she's sent me several pm's that I never received. This isn't a constant issue as other members were able to pm me at the same time or same day and I was able to respond to them. However, it is the first time I've used the actual 'New PM' button and chose the recipient from the list as I usually just either respond to a pm or click their name and send them a pm that way. So not sure if this is an issue with the direct sending from our pm page or just something that comes and goes. Help please.
http://animedohyou.phpbb9.com

What happened when you hit the send button?

It went straight back to the 'Inbox' page like it usually does. I didn't notice anything wrong, and had I not tried to read it from the outbox, I wouldn't have known that it didn't send.

Were you typing the PM for a long time? Like maybe 5 minutes or more?

Yea, about that. It was a rather lengthy pm, but most of my pms are lengthy and it's never happened before. Has there been a timeout added?

It could be possible. Why not try to write the PM in MS word & then try to send it.