m00t, the good news is there are programs and companies that can recover your data still. It seems as though it's only been partitioned. Sometimes these programs are free to prove they work, but then you have to pay $30-50 to actually be allowed to move this recovered files to a working hard drive. Or you could send it in and it may cost you hundreds of dollars. If the data was priceless to me, I'd send it in. The IDE controller you put in later did not lose your data, a faulty windows installation did this.
A word of advice for users whom may be reading this in the future. Using Win XP cd before SP1 does not support hard drives larger than ~131GB. If you continue with this, you risk losing data on all connected hard drives that are larger than ~131GB. If you notice windows installer not recognizing your true hard drive size, stop and consult help. Trying to use windows disk manager to fix the problem wll make things more complicated.