A/C problem, I need help
 

The car is a 1991 300E/2.6 and my problem started after my friend and I charged it with freon.
My A/C quit a couple months ago and I knew it's because of low refrigerant. I finally got around doing it yesterday. We pumped about a pound of freon and the clutch engaged and vents started blowing cold air. A couple minutes later, I noticed smoke coming from the compressor area. We shut it off quick and after several re-starts, I found out that the smoke was coming from the belt caused by the compressor pulley not turning. Is this an indication that the compressor froze or binding inside and I'm looking at possiblly needing a new one? Is the compressor that heavy to turn that it will cause the belt to slip? The belts were replaced 3 months ago and I am not sure it was adjusted right.
Can somebody please give me some insight on what is causing the belt to slip like that and what to do next. Thanks in advance.

Jim

My recommendation is to replace the compressor because it is dying a slow death. If you keep trying to run it you could possible dump a bunch of compressor internal parts into the a/c system and could result in having to flush the system.