There is a way to use dropbox with Quicken. I have been doing it for a month or so now and I have it installed on four computers. I wanted to find a way to access my quicken data no matter where I am at. Here is how to do it. On your first computer, place all of your quicken files in the dropbox folder. Let it sync to the cloud (your dropbox account). Close quicken on that machine.
Then install dropbox on the next computer and let it sync. Then install quicken on that computer and direct it to the dropbox folder for the data files. You can continue this on an unlimited number of computers if you desire. The key to remember - you can only have Quicken running on one machine at a time. The next thing to remember to make this work is before you open Quicken (on whatever computer), you have to pause syncing. You do this by "right clicking" on the dropbox icon in the tray.
When you close Quicken, remember to resume syncing. This process will let Quicken write to it's local data files without any interuption from Dropbox, and whenever your through and resume syncing, it will bring all other computers up to date. It works great for me. Just remember, one person at a time in Quicken, pause syncing before you open Quicken, and resume syncing after you close.