MacBook Pro connected to Dell monitor display issue I have rather a strange issue when I try to connect a dell monitor to MacBook Pro.
Firstly the Dell monitor won't detect the signal from MacBook if I connect it immediately after the laptop is booted. It takes a while (I didn't measure how long) for the monitor to detect the signal from MacBook after lot of attempts.

This is not the end of the problem. If I want to log in back after my MacBook goes to sleep mode, then it won't wake up. I have to disconnect it from the Dell monitor in order to log in back, worst of all sometimes I need to force shutdown the MacBook to log in back.

I am using a DVI connector from Monoprice to connect the Dell monitor to my MacBook. 

What could be the issue? Any help is appreciated.
Given that nobody seems to have any idea what the solution might be, I'll give you the Ask Different Backup Answer to Hardware Problems (aka ADBAtHP): go to your local Apple Store (or Apple Authorized Reseller) and ask them. Take your Mac, the adapter, and the monitor so they can reproduce it. They'll probably try other monitors, other adapters, and other Macs to see what the issue might be. Hopefully you're under warranty and/or it's just a bad mini DisplayPort adapter, as that's the cheapest fix.