Serious Issues with Backup/Restore - Installation now broken

Hello,
I'm currently at my wits-end, due to now having my OC website down for over a week, and would really appreciate some help from you experts! I might be able to cut this long story short, but:

sunplastics.co.uk/buy
Running 1.5.4 installation, with vqmod installed, sucessfully for over a year.
I decided to backup (from admin rather than phpmyadmin) and backup ftp files/folders, to attempt an upgrade to 2.0.

This didn't work. So to avoid my website being offline, decided to re-install and make further enquiries.

This is where to trouble began. I thought i'd be able to simply delete the upgraded files/folders, and restore all with the backed up files/folders. This failed, and I was presented with the blank screen.

Upon searching the forums, i've installed the error log into my index, which i tried to rectify unsuccessfully.
I've tried to re-install the database backup into a fresh install of 1.5.4, but admin tells me that the sql file is empty! (it's 17mb - and it's not empty!)

I've tried all i can to get back online, but frankly i'm stumped. Can anyone help?

Thanks,
Kevin

Yep youve got a problem.

You probally have to go through your entire sql file, correct it where needed and than import it through phpmyadmin to restore all data.

if in your original shop you had any mods affecting database, trying to reimport it on a standard database does not work.
trying to import a exported database from opencart in phpmyadmin will not work.

so the only solution is to manually configure your oc exported database so phpmyadmin will accept it and all is restored.

I had a similar problem - turns out you need to check that the config files need to match your database prefix. One version has 'oc_' in front so make sure your config files in the root and admin mate up.