Unfinished IT projects

It happens all the time. It can happen for a variety of reasons.

1. The client may not have liked the previous contractor's work, ethic, communication style.
2. There may have been fundamental differences in the perception of the requirements (i.e. the client wanted feature X, contractor built feature Y)
3. There may have been cost overruns and delays the client considered unacceptable.
4. There may have been technology choices that the client can't support.
5. There may be technology choices the previous contractor insisted upon that the client refused to shell out for.
6. There may have been fundamental philosophical differences regarding components or delivery (security, continued support, access, etc).
7. The client may actually be trying to get the project completed by screwing a series of contractors until he only pays for the final piece to finish it (reducing a $25,000 project to $3,000 - or whatever currency is agreed upon)
8. The previous contractor may actually be trying to get more money out of the project by attempting to upsell different features, delay required features, or putting in add-ons the client didn't ask for.
9. The client ran out of money on the first go around. Now the previous contractor is unavailable due to a competing contract deadline.

This is not by any means an exhaustive list, but these things happen on a regular basis. They're all part and parcel of the whole contracting gig. Being able to overcome some of these is a huge part of completing a contract. Being able to recognize the ones that negatively affect you (or your business) is very important to maintaining a positive reputation in your area (assuming a local rather than online presence).