Motorola V710

I am trying to get a song from my computer on to the phone for a ringtone. I know the procedure but something is going wrong. In Itunes I convert the file into one of about 25 to 30 secs in length averaging 235 kb in size (imported a 64). The extensions are changed from mp3 to mid and then emailed via vzwpix.com. However after receiving the email/message and trying to download the files the phone says the files are too large. Previously these sizes were perfectly fine and in fact some that were larger worked (on a different v710) Has the software changed or is there a size limit now?

Thanks