jQuery 1.2.4 was a bad build. The jQuery team released jQuery 1.2.5 today. I made a new post for jQuery 1.2.5 with Intellisnse.
jQuery 1.2.4 was released yesterday, so I wanted to update the jQuery Intellisense file I built for jQuery 1.2.3. This is the full jQuery library with XML comments added to it so that Visual Studio will display intellisense hints for you.
Also, you must have the Visual Studio 2008 Hot Fix Roll Up Patch installed.
From looking at the source, there isn't a lot of new code in the update. They've added four functions from the jQuery Dimensions plugin: innerHeight(), innerWidth(), outerHeight(), and outerWidth(). Other than that, there are a few changes to a few lines which I assume fix bugs. For details you can read the jQuery 1.2.4 release notes.
It was really quick to update the library with the XML comments. Using WinMerge, I loaded the jquery-1.2.3-intellisense.js file into the left side, and the new jquery-1.2.4.js file into the right side. Then, I just went through the differences, and merged the XML comments from 1.2.3 to 1.2.4. As far as I know the only API changes were the addition of the four functions from dimensions. For these I used the documentation from the dimensions page since I couldn't find them in the jQuery documentation. It actually took longer to write this post than to make the updates.
If you run into any problems with the update, let me know and I'll fix it and post it. Good luck!