Thank you for your comments, perhaps you could provide some more information of what you are searching for and what isn't appearing etc, what features are lacking that you used before.
It is still being improved upon so things will get better, but it isn't a simple issue to resolve. On a small forum, the search is easy, you can look through all the posts for each search and get results on the fly. Once the forum gets to a certain size an index needs to be built otherwise a search can bring the server to its knees. The way things are indexed and cross referenced is something that needs to be balanced with the size of the site. Currently to index the DIYnot forums, without including the General Discussion forum (i.e. 100K posts less), is taking in excess of 8 hours.
If you could post your feedback here or in the original post in Forum Info here, it would be appreciated.
As a further update; a problem meant that searches containing numbers would return no results, so if your search has contained a number and returned zero results this is why. This is now resolved.
How can you search all posts made by a particular individual - there used to be an "author" field. This was useful to find you own previous posts or to gain further informartion on another poster.