Assuming you are speaking about the website you link from your signature, the problem is most likely with the contents on your website.
On-Page Contents:
I went through your website and don't it seems to be a bit downside on both language and sales point of view. There are enough keywords but that is not the way it is supposed to be written. Try hiring a professional content writer and re-write your website contents.
Google naturally loves a website with a user friendly content (in a well written format). Poor contents written hastily just for including on-page keywords, will not work (no longer).
Links to your website: I am not sure whether you are monitoring the links that ping back to your website. But some of the links pointing to your website are really low and badly hit by recent Google Updates (possibly Penguin). You can easily say that by "N/A" (as their PR). Disavow them on Google Web Masters tool, it will remove any bad effect they might have caused, then focus on improving adding some good quality relevant links.
Some links (from directories) are submitted in wrong category of directories, check them too, you can use the mail ids you used to edit(applies in most reputed directories), other wise you can Disavow those links.
This forum for instance is directly related to SEO, Web design and other similar web related topics, and links from here are not exactly relevant to your website. So consider finding forums, blogs and directories that are relevant to your industry. Lately Google recommended links from relevant website much more important for ranking, consider it too.
All the best for your SEO efforts...!