The discoverability and structure of your community/forums web is one of the worst I have seen. Every time I want to find the answers to a question through your forums I get irritated and usually end up giving up.
I would wager that of all the visitors to your web site the majority is existing customers who want to find an answer to a question about one of your products. This is just an assumption, it could be wrong. But one thing is certain, you have many visitors of this type, and I am one of them. I use Resharper and would love to learn more about the product by reading forums with questions and answers from other Resharper users. And most often I have a specific question I need an answer for.
Finding the forums
So lets assume I come to www.jetbrains.com to look for an answer. On the first page there is no link to forums. There is a box for each product with some four, five links in, none of them to the forums. So I click the name of the product, and get to a page with some information about the product and six tabs for different information, but no link to the forums.
So I try the Community link at the top of the page. On this page if your scroll down you can find the products again with some links, and look here is one called Forums under ReSharper. Clicking that I expect to find forums, but I dont, I get to a list of blogs written by JetBrains employees. And at the bottom there is a list of "New Documents", this list I don't even get, its a bit like a forum, only there are no threads and it seems to be links only to stuff written by JetBrains employees.
A useful forums needs two things:
1. A list of threads (by subforum if applicable) with information about post dates and number of posts in each thread and the ability to read one such thread.
2. A good way to search the forums.
These features may exist on jetbrains.com but if they do, they are so hard to find my critisim is still the same. I really think you should take a serious look at this as I feel you are wasting an opportunity and your customers' time.