1. Which version of Oovium Mind Mapper are you currently using?
2. Which device are you using? (iPad 1,2,3; iPhone 1,3G,3GS,4,4S,5; iPod)
3. Which version of iOS are you using?
4. What is Oovium Mind Mapper and dropbox doing? Keeps asking you to login?
I'm sorry you are having trouble; hopefully we can get this figured out shortly.
Also, I'm not sure what you are trying to do at the moment, but you can also use iTunes to access the Oovium files. If you connect your device to iTunes and then select it from the iTunes pane, then select 'Apps', scroll to the bottom to the 'File Sharing' area and then click on Oovium Mind Mapper a list of your documents will appear that you can then copy and drag to your computer.