I have a MES30 and use it quite frequently. I have also had concerns that I wasn't getting enough smoke from it. Here is what I have found out about my smoker over the last two years:
1. If the heating element isn't on and hasn't been on for some time, it probably stopped producing smoke. Quite simply, the wood chips need a heat source to burn as they won't sustain burning for long on their own. If the smoker is "at temp" and the heating element not on, it ain't smokin'. That is sort of a give/take with my MES30. The insulation is great and will hold temp inside even when it's below freezing outside. The dowside is that it will sit there on a warm day and not run the heating element for long periods. That said, over the course of an entire cook it usually produces enough smoke during the heating intervals to get the job done. So, over the entire time, not much to worry about. Some ways to combat this is to incrementally raise the cooking temp as one fella suggested above. Pre-heat to somewhere around 180 then when you put whatever it is in the smoker, raise the temp to 200 and toss in some chips. Once it hits the 200 mark, raise to 225. If you care to step it up to 230-240 after that..go ahead.
2. Don't oversoak your chips. Or as I have taken to doing, don't soak them at all. If you really feel compelled to soak them, I would recommend more just giving them an extended rinsing as opposed to a real soaking. I only wet my chips if I am having troubles with flare ups, which doesn't happen often.
3. Use small chips, not chunks. I take it a step further and mix in a healthy dose of the dust that I use with my Amaznsmoker with the chips. A good large 3 fingered pinch or two per 1 handfull of small chips.
4. Don't stress on it. Like I mentioned in #1, over time the MES puts out enough smoke to get the job done (in most cases). If you are one of those that likes a strong smoke flavor you may not get it just running normally, but it will get a smoke flavor though the meat. As others have stated, a lot of times you won't see the smoke, but if you sniff over the vent on the top you will get a smokey smell. That's all you really need.
5. If you do want a stronger smoke to your creations, which I do on occasions, I just crack the door a bit to drop the temp inside the smoker down enough to kick the heating element back on. It's kind of a pain to constantly have to go out and kick on the heater, but it works. Also, I will pull out the half burnt chips and replace them with new chips/dust. These tend to burn more redily and produce more smoke. I don't often follow this step, but if i feel like I really want to have a powerful smoke flavor, I will.
Good Luck!