If you think the Dock Connector to VGA Adapter is not working with your Apple iPad 1, it may be because the adapter does not allow for full mirroring of the ipad. It is important to realize that Apple has restricted video out to the following limited list of apps for the iPad 1:
Photos - Slideshow playback only
Safari - Video content on webpages
These are the only native apps that are currently supported in conjunction with the VGA accessory cable. Some apps do allow for use of a VGA adapter. Here are a few:

2Screens - Presentations
A full featured document manager allowing display of web files, PDFs, Office files, iWork files, and images.
Draft Notes
With a VGA Adapter plugged to your iPad, both your document and drafts can be shown simultaneously on a secondary screen.
Keynote allows you to create amazing presentations, with beautiful Apple-designed themes, custom graphic styles, and stunning animations and effects. Great transitions too. And they will all display nicely with a VGA adapter.
Uses the VGA adapter to display web content.
Use this app to display a webpage on a TV, projector or monitor from your iPad or iPhone.
TweetBoard is an app that displays Twitter tweets.
Your handwriting and drawing will look great using the VGA adapter. You can use a stylus or your finger to make those notes and drawings.
Store and view documents on your iPad. Upload using iTunes, Wi-Fi or transfer from another app. Display onscreen or on an external monitor or projector.
Box.net lets you easily access, view, share, and collaborate on files(5 GB Free) from your iPhone or your iPad.
Pocket Universe
You can literally hold up your iPad in front of you, and the app will use the built-in compass to display the same view of the sky you see - but one that's complete with names and information.
Art Authority
Be transported into a real world art museum with the greatest works of art from all time. Search for artists and paintings or just browse.
Office 2 HD
the most intuitive and straightforward office document editor available on the iPad, makes it easy to open, view, create and edit Word (DOC & DOCX), Excel (XLS), and now PowerPoint (PPT) files right from your iPad!

VGA out for displaying web pages.
For displaying web pages on screen.
No laptop? No problem! With iDemoWeb you can present your web site or web application directly from the iPad to a room full of people.

With the advent of the iPad 2, this is no longer an issue. iPad 2 totally mirrors your iPad's "desktop" when you use the adapter to connect an iPad to a projector.