Migrating from Outlook 2007 to Entourage 2008

Question

15 days ago, I bought my first Mac after a 12-year gap. I have been trying to get my information from Outlook 2007 into Entourage 2008 without any luck. I've google'd and found that there are indirect paths only. (via mbox).
My E08 refuses to recognize the mbox files. After renaming my Inbox files as Inbox.mbox, they show up as E08 files (with the E08 icons). But I cannot open them in E08. When I go the File, Import method in E08, all mbox files are grayed out and I cannot select any of them.
I've installed Thunderbird on my Mac and got all the files into Thunderbird from my Win PC. Apple Mail crashes consistently when I try to import from Apple Mail.
Total file size is 5+ GB with 30 folders. Any ideas on what I may be doing wrong.

Answer 1

Here is a long pending update on how I got my OL2007 data into E2008.
On the PC:
1. Setup Gmail Imap in OL2007. (I used my Gmail account for this purpose. Go into Gmail and search for "Outlook Imap setup")
ENSURE ENTOURAGE IS NOT RUNNING ON THE MAC.
2. Drag and drop each sub-folder from the Inbox into the Inbox of the Gmail Imap folder.
3. Depending on the size of the sub-folder and attachment, it makes take a few minutes to a couple of hours.
On the Mac:
4. Setup the Gmail Imap folders in Entourage too. (again refer Gmail help section).
SHUTDOWN OL2007 ON THE PC
5. Drag and drop the subfolder you created in step 2 onto your Entourage Inbox. (because this is a "download", it might work faster).
6. After step 5 is complete, quit Entourage.
7. Back to your PC, start OL2007.
8. Drag and drop the sub-folder from Gmail into the OL2007 Inbox. (this step is required if you want to preserve all the data on OL2007).
9. Repeat for other folders present on your OL2007.
This process is excruciatingly slow and painful, but it did get me all my data, attachments, preserved the links intact and organized it according to categories. For categories, ensure that you create the same categories as your OL2007 on E2008.
Good luck.