There can be many reasons for a site for not getting spidered.Some of the methodlogy while making a site which could have gone wrong are:
There are many pitfalls in web designing that can hinder a spiders ability to completely (or even partially) index the content within a given page. One of the biggest mistakes webmasters are still making is that of using “frames”.
Frames are a design convention used to utilize independant scrollable regions within a single URL designation (or so it appears). Frames are actually divided into multiple URL designations and are generally not spiderable by the search engines.
To have a site with a flash image is great, it will impress your visitor and increase the estethic quality of your site for sure, but this flash must still be accompanied by a healthy portion of good old fashioned text, written in html, and readily accessible to the SE spiders.Limited use of flash should be done allthough now Google does spider flash site as well but still not as the simple HTML sites are done.
If you are still having problems getting your site indexed then you should get in touch or hire an expert website maintenance team team who can help you with different aspects of website coding. They can find out the issues and fix them as well for you.