Hey,
Is it maybe something to do with the Dropbox Version 1 API deprecating? https://cloudrail.com/dropbox-api-v1-deprecated-upgrade-cloudrail/
I do work for CloudRail. We’re actually currently working on a PHP SDK for our Single Interface (in short, abstracted APIs using the same function, with Dropbox included as a service) that should be ready in about three weeks. Should be good as, to my knowledge, Dropbox have said they won’t be supporting PHP in the next release.
Hüsken, if you are interested, send our CEO a message: [email protected]. He can talk about the PHP SDK with you, give you some technical advice, and maybe even a sneak preview. (Bonus, he can do it all in German! Alas I still find the language very hard to learn.)