From Dropbox –

“Hi,

We noticed that you’re running the Dropbox desktop application (client) on an older operating system (OS X Tiger 10.4 or OS X Leopard 10.5). We’re writing to let you know that as of May 18th, Dropbox will no longer support these older versions of OS X.

Don’t worry — your files and photos aren’t going anywhere! But you’ll need to update your computer to OS X Snow Leopard 10.6 or later to access them through the Dropbox desktop app. Apple’s instructions on how to update your operating system can be found here.

If you don’t want to update your operating system, your files will still be available through the Dropbox website. However, on May 18th you’ll be signed out of your Dropbox account on your computer and the Dropbox desktop application will no longer be accessible.

We apologize for the inconvenience. For more information, please check out our Help Centre.”

Personally don’t see a problem with this as these are really old operating systems now. Does this affect you.