config and stuff gets resettet

Hi,
sorry, the title may be missleading.

I bought the theme some days ago and installed it on my webspace.
I played around for a while and on next day i got the following sentence:

Error connecting to Database (may be something else in english, i’m german native)

After some dancing around on the FTP i found out that the wp-config.php has not saved all information e.g. username and password. I retyped everything and uploaded the file again. It worked.

Next day i wanted to continue my work on the theme i saw the same error again, checked the wp-config.php file – and again the same things have been replaced by the stuff which was in the day before (only username and password)

Also the WordPress update gets installed everyday i have corrected the wp-config file. So it seems that somehow my whole wordpress folder gets resettet it was the day before?

My webhost told me that it has may be to do with the theme or some plugin with FTP rights. He tryd to help me and changed some stuff (i have no clue what he has done) but the same thing happend again today.

I dont know if my whole work gets replaced to the day it was before if i work on the page – but our page will only be online beginning in the early morning i swap the settings and till late evening.

Can someone help me here?