Time Machine malfunctioning: Back up created but not up to date

Hello everybody,

a few days ago I backed up my computer using an external hdd and time machine. I then formated my internal drive and reinstalled osx.

When I wanted to get my data back by entering time machine, I realized that time machine had created a sparse bundle with the date of the back up, however when mounting the drive only the 'portdetect.log' file was updated. The user file is from a much older date. The same accounts for 'Library'.

Now my question:

- Is there a chance that my up to date data was still saved on my external hdd in some way? I already verified and repaired the external drive using disk utility. Everything seems to be ok.

- I used Stellar Phoenix to try and access my old file partition. I found two volumes, one of which was empty. However I could only retriev some files from the other one, including a 90GB sparse bundle that is unable to be mounted ('not recognized'). Has somebody an idea how I could reaccess my files on the internal drive?

Basically I need to get the data back I trusted to be backed up with TM at the time. Very angry about the fact that the back up did not work properly.

Hopefully there is a way to retriev the old data.

Thank you for your help!