I recently contacted EA direct through their support pages and have had a response regarding the melee stopping working issue unless you restart the game.

They have said that they do not know when this issue is going to be resolved!!! they also say that its NOT a technical issue!!!!!!!!! WTF!!!!!!!

the response from EA is pasted below :-

Hello,

Thank you for contacting Electronic Arts.

I sincerely apologize for any inconvenience caused to you and extreme sorry for the delay in response. After reviewing your issue the situation seems to be more game play related rather than something we can resolve through technical troubleshooting or adjustments to your account details. We would recommend searching for answers through the games forums at http://www.gamesas.com/forums/ to see if other users have had similar trouble. If you find other users have similar problems in the forums, then I suggest you to post the same over there. So, game developers can be aware of the issue.

These forums are maintained and monitored by the community leaders/game developers and production team also visited by several other players. By posting on these forums you will be able to submit direct issue/feedback/concern to the appropriate person (Game developers).

We will also pass the information you have provided to the development team. Regretfully we do not have information on if or when a fix will be put in place if this comes to be a glitch.

In the mean time, I am notifying my supervisor that you have an unresolved problem that we have no fix for. For your inconvenience, please accept my personal apology that this problem negatively affected you.

I hope this helps.

When you play the game and if you think the game has a glitch or fault you are best giving your feedback in the right place, i think there is a sticky thread for this here. I have noticed some sound related issues, a possible stealth kill issue which i'm not 100% sure if it is melee related in sp mode?