Install Quicken 2007 on Snow Leopard, open your files, quit Quicken 2007. Contrary to Quicken Support's info, it *does* open Quicken 2003 files, I just did it. Clearly it should open more recent files too, but mine were 2003. Then Quicken seems to automatically update and re-save them. Now the file(s) can be opened (not imported) with Quicken 2007 for Lion.
Yeah, it's actually really easy, provided you have both a Snow Leopard and a Lion system, and the two corresponding Quicken 2007's.
Oh, the Lion version is available for $15 on the Quicken website somewhere, and Support will give you a link to the Snow Leopard version I think.
I was able to convert my 2003 Quicken files to Quicken 2007 files in Lion. There are several steps. You need two computers, one with snow leopard and your original quicken files, another computer with Lion; you also need two different versions of Quicken for Mac 2007 (old version) and the newer Quicken 2007 for Lion.
You can find the old version on line (and I may post mine on Ebay) and the new version from Intuit for $15.
Install Quicken 2007 for Mac (Old version) onto your computer with snow leopard and your Quicken 2003 files. You can then convert your 2003 files to 2007 files (old version). Copy your data file (i.e. the file with your quicken accounts) and put the copy on the computer with Lion. Install the updated version of Quicken 2007 for lion and it will open the data file copy converting it to Quicken 2007 for Lion.
Have faith…there is a way. BTW, a Quicken customer service rep in New Delhi talked me through the installation and conversion.
Good luck. (this answer was posted earlier; I am just giving a little more detail.)