The most common mistake I see technical entrepreneurs make is when the entrepreneur pushes solutions onto a market without talking to real customers in that market. Getting feedback and input is the life blood of an entrepreneur. More is better than less because it lowers the likelihood that you get steered in the wrong direction.
I know this because I made this mistake in the past -- and spending years pounding one's head against a market wall pushing is not fun (take my word for it). I now am increasingly obsessed with the amount and type of market research that entrepreneurs do before building product.
Before talking to me about investing in your company, make sure you've really interviewed and understood at least 10 potential target customers.