How to stop Vuze from opening at start-up on Mac?

[blahbyduh]

Hi all,
Basically the title - I've gone to Preferences and I'm not able to uncheck the 'Start Vuze on login' option. It's faded.
I've tried googling it but no one seems to have had a similar problem. Can anybody help? I use a Mac.

My internet service provider is StarHub and i use wifi.

Java 1.8.0_92 (64 bit)
 Oracle Corporation
SWT v4528, cocoa
Mac OS X v10.12, x86_64
V5.7.3.0/4 az3