It's an intrinsic property of HTML form elements. It's not that somebody would tab their way to these fields to press enter, there's just no reason to block a function that's already there. I'm sure you'll find most forums work the same way. Deal with it.

hmm, i think that's true for most logins or search functions, but for board/pm systems? i don't believe so. besides, why would anyone want to click into one of these 2 fields after composing the message and then press enter to send if you can just click on the send button? for keyboard users it doesn't make sense either because you'd have to hit tab a million times to get back to these fields, or press some weird shit like shift+tab+backspace.

in short, if someone presses ENTER in either the to or subject field, it's most likely to have been an accident, and should result in either no action or behave like TAB.

but if i'm mistaken then never mind.

Enter is the standard key for submitting forms when a one-line input is focused. It has been that way forever on the internetz. However this board also allows you to press ctrl+enter when the text area is focused in the send PM view, since enter just starts a new line.

on composing a pm, if i accidentally press ENTER while cursor is in either the "To" or "Subject"  fields, the board system tries to send the message. (using firefox on ubuntu)
may not actually be a bug but it's quite confusing since the tooltip over "SEND" reads "CTRL+ENTER".