Okay finally the Sales managed to call the customer, which lasted an eternity. After that, he transferred directly to me.

Customer: "Aiyo why took so long to call me ar?"

Now, that's a very unrespectful phrase. Here I was trying to call him, and his line always engaged / not picking and he gave my that kind of remark. Not only that, I had to stop taking calls and talk to this idiot instead.

Me: "We're actually supporting other customers, so if you understand, I have other obligation as well. Anyways, how can I help you?"
Customer: "I want to connect to NT Domain of the system."
Me: "Huh? I don't think you can because PDAs are supposed to be a simple system doing light chores like editing documents & reading off documents."
Customer: "But I want it to get connected to the NT system..."
Me: "Other way is to use a VPN."
Customer: "What's a VPN?"

Oh boy. Now I've done it. Didn't realized the bloke was THAT stupid.

Me: "VPN stands for Virtual Private Network. It's where it will encrypt your connection so that it can establish a secure connection to your NT domain."
Customer: "Okay, I think I have the server. How to I configure them?"
Me: "Eh? Actually I'm the support for the PDA, not the server..."
Customer: "So how?"
Me: "Get your technical guys to do it then..."
Customer: "What about connecting to the internet?"
Me: "Well, you've got to have a proxy machine as well."
Customer: "What's a proxy?"

Another mistake.

Took another 5-10 minutes explaining to the idiot what's a proxy. Finally when I put down the phone, the Sales quickly call me up and asked for the outcome. Told him customer wasn't practically smart.

SM: "You know, that fella is the IT manager you know..."

*sigh* Here's something I've learned: The higher position employee is inversely proportional to the intelligence.