I can't even count the number of times that I have heard "i can't understand my IT guy". A wise man once told me "if you do not understand someone talking technology one of two things is happening, either they do not understand or they do not want you to understand". If you cannot understand your IT person, a technology sales person, the people who service and support your technology how can you trust them. You need to understand so that you can make educated decisions. Now understanding does not mean you need to get into bits, bytes and all the minutia. It does mean you need to be able understand at a level that makes you comfortable that you can make sound decisions.
For the listener - you deserve to understand:
I have been in many meetings where I have asked to have the conversation slowed down. I deserve to understand. I use the line "talk to me like I know nothing about technology". This can help frame the discussion. If the discussion gets to simplistic then the dialog will bring it back up to an appropriate level. If this does not help then you have to ask if the person understands or if they don't want you to understand. You need to take action and find someone who can help. This may be require a change in the person you are talking to or someone who can act as an adviser. Someone who can talk to the techie and then revise it to make it understandable to the professional.
For the presenter - it is your obligation to help your audience to understand:
Often time we live so deep in our environment that we are used to talking at a level that everyone in the "office" understands. We forget that our prospects, bosses, or clients do not live in this world. I have often used the "significant other" test. Explain your topic to a friend or significant other who is not in the tech industry. If I can make that person understand I may be speaking at an appropriate level. When I make technology recommendations I tell myself am I framing this in a way that my audience will understand? For example if I am working for a City or a County I want to make sure that the recommendation can be clearly understood by a Board or Council member.