In reply to Profanisaurus Rex:
OK, weighing up the options logically.
If you don't chase, nothing changes.
If you do chase, it's unlikely to affect the outcome badly. Particularly if you are your usual charming and articulate self and that I know you have the sense to back off and end the call if you feel the recruiting manager is reacting in a less than positive way.
But I wouldn't spin them a line about wanting to know because you've had other offers; it sounds like you're trying to force their hand. Just be honest - you would be very interested in knowing the reason for the delay, even if you can't affect that, because you are particularly interested in the job and would be keen to know how likely your chances are at getting it.
I think I'm saying go for it.
P.S. Am in after 9ish tonight if you want to chat