I cannot sync new files into my dropbox, since my dropbox "is out of space". however, im only using 1.3 GB of storage.
If Dropbox is saying you're out of space, then you're out of space. You can check the actual usage in your account on your Plan page. It will show you a breakdown of the regular, shared and available space in your account.
additionally, my dropbox has only shared folders - and other members of the my group dont have any problems uploading new files.
Remember that shared folders use space in your account as well. The other members likely have more available space in their account, so they're able to upload new files to the shares.
ok, I looked it up further, as suggested: it seems that we are using a business account and its "trial ended". im not the admin, but it seems that I dont have personal account that is separate d from the business one. otherwise, why dont I have the full 2 GB storage?