Indexed site absent from Google search results-why?

Do you use Google webmaster tools?
That might help you
www.google.com/webmasters/tools/

It's free and I find it a useful tool. If googlebot had any issues it will log them and let you read them.
I would try that first, if that doesn't list any problems then I really don't have any suggestions. I searched for a few things for your site and most where top of page one.

Just a note:
You have 101 keywords in your HTML.
Although I can't see that causing your site to fluctuate hugely from page one to nowhere to be seen, and really Google doesn't use meta keywords very much anyway.
But not knowing their exact algorithms they might mark it as spamming or keyword stuffing, although keyword stuffing is supposedly for hidden page content, rather than meta. I don't know, perhaps they include meta in that blacklist function now.

Well you do rank first for "Vancouver Art Show" (with and without quotes). If you're looking for rankings on more general keyword phrases there are some other things you should do.

I'm looking at your site in text only mode with tables disabled and the text just doesn't make a lot of sense. This is how a search engine is going to see your site - no page layout, just text as it appears in your HTML source. It would be good to have a text description of the site up top that includes some good keywords. THat would also tell human visitors what they can find on your site.

The title tag doesn't include any other keyword phrases - you can include up to 65 characters in your title tag. Use that space to include some additional keyword phrases (will still keeping it readable for humans).

Your inbound links aren't really great quality. They seem okay to me but there's a lot of repetition from a few sites (my mom visits that wet canvas forum!)

I also think that the design of the site and the navigation aren't doing you any favours. The links aren't well labelled, it's difficult to navigate, and there aren't a lot of keywords in links or URL's. A mediocre design makes it less likely that other sites will link to you voluntarily. Poor navigation adds to that problem, and also makes it more difficult for search engines. You shouldn't have to explain how to navigate your site.

This poor navigation and site structure could explain why a lot of your interior pages don't have page rank. I'm finding that some of them do rank quite highly (Artist Neil Woodward for exampe). It's not really normal for a PR3 site to rank for common keywords.

I'm not really sure how DNS problems would cause search ranking problems, but all of the above issues are quite significant when added together.

Thanks, Megan and Greg. I am actually quite familiar with Google's Webmaster Tools. It's reports for my site indicate that there are no problems crawling and indexing the site. I know there are improvements that can be made to improve my page rank, which is currently at 3, but normal SEO doesn't seem to be the issue here.
The problem is that in spite of the fact that the site is fully indexed, has a positive page rank, and hasn't been blacklisted for any Guideline violations, it still doesn't come up in the search results - not even a thousand pages deep - except when the search words used are the actual name of the site, or very close to it, as Megan has pointed out.

That's normal considering that most of your secondary pages don't have PR. At least as of the last toolbar update and you say the site is a year old. I'm testing some pages and usually I can find them in the SERPs with the intitle:modifier.

I think the main problem here is that poor site structure is preventing PR from flowing to secondary pages. You're talking about the site having a PR of 3 but I can't find any toolbar PR for other pages on the site. There hasn't been an update in awhile so that may have changed.

Edit: another thing to keep in mind is that toolbar PR is not the same as the internal PR which google actually uses to rank pages. Your "real" or internal PR could be higher or lower than what appears on the toolbar. Toolbar PR is usually about 3 months out of date when it's posted. It's also rounded (not exactly sure of the details on how the rounding works), so your actual PR could be 2.6 or something like that.

What I'm seeing in your SERPs looks similar to the old supplemental effect - the pages are only coming up when G can't find anything better to match the search query. The way to fix this is to use the same methods that used to be recommended for getting out of supplementals - build better quality links, and work on internal link structure to make sure incoming PR gets distributed to other pages.

How long have you had the PR 3? It doesn't make sense that it's not flowing to other pages unleess it's either new or there's an internal linking problem.

Another thing I just noticed (duh!) is the the phrase "Vancouver Art" doesn't appear on the page until about halfway down (other than in the title tag). Try fixing that and see if anything happens. It would also be good to get some inbound links with those keywords as the anchor text. The brief appearance in the top results could be explained by a variety of factors - google making adjustments to the algorythm being the most likely.

I also just realized after looking at your code is that your main navbar is done as an image map, which explains why PR wasn't being passed on to your other pages. The HTML code in general is really bad and probably isn't doing you any favours with search engines.