attachment views and pager
If you're using Views 3:

While I don't know how to exactly do what you want purely with Views (or even if it's possible), I can suggest you a module called Display Suite which can work with Views. You can define different display modes for nodes first, and then go to Views and choose "Node Display" type of output, and define in the settings which article should be displayed with which display, for example First 3 nodes in the list should use "Teaser with Image" display, next 3 would use "Teaser without Image" display, and then the next 6 would use a normal "Teaser" display. Then you can use CSS to define the columns for the last 6. Doing it this way you eliminate having the need to use Attachments, so all your results come from 1 display. Pagers then should work normally. I cannot guarantee you this will work 100% as I haven't used this module by myself, but I've seen a colleague implement something like this before, and he also had problems with using Pagers. I'm not sure if this functionality is compatible with Views 2 as it's been a long time since I used Views 2. Good luck.