The card limit has been raised to 40 cards per an account.
I believe that 4 cards can transfer at a single given time. That being the case, if you have 7 cards, only 4 will be transferring at one time.
Could you provide the card log with that message? It would also be useful to take a look at your helper log. Here are instructions to retrieve both:
Eye-Fi Card log recovery process:
1. Insert your Eye-Fi Card into your camera
2. Take 5 pictures
3. Wait 5 minutes to give the photos a chance to upload
4. Remove the card from your camera
5. Insert the Eye-Fi Card into the USB card reader and into your computer
6. Click on the Eye-Fi Helper icon in the Apple Menu Bar or in the Windows Task Bar
7. Select "Get Eye-Fi Card Log..." from the menu. You may have to wait several seconds, but, in a moment, you will be asked where to save the Eye-Fi Card log file
8. Save the Eye-Fi Card.log file to your computer hard drive and reply to this thread with your log file attached
Eye-Fi Helper Log for Macintosh computers:
1. Close the Eye-Fi Helper software agent icon running in the Menu Bar in the upper right-hand corner of your screen by clicking one time on the icon and selecting "Quit".
2. Double-click on Macintosh HD on your Desktop.
3. Double-click on the Users folder.
4. Double click on the icon with the <computer user's name>.
5. Double-click on the Library folder.
6. Double-click on the Eye-Fi Folder. Reply to this thread with the file EyeFi.log attached.
Eye-Fi Helper Log for Windows XP computer:
1. Go to Start, then My Computer and open that up.
2. Double click on local disc c:
3. Double click on Documents and Settings
4. Double click on your user name
5. Double click on Application Data folder
6. Double click on Eye-Fi folder
7. Save the EyeFi.log file and attach it to this thread.
Eye-Fi Helper Log for Windows Vista or Windows 7 computer:
1. Close the Eye-Fi Helper software agent icon running in the system tray in the bottom right-hand corner of your screen by clicking one time on the icon and selecting "Exit".
2. Right-click on Start.
3. Select Explore.
4. Open this folder: C:\Users\<computer user’s name>\AppData\Roaming\Eye-Fi\
5. Reply to this thread with the text file titled "EyeFi.log" attached.