I find it rather strange that no matter how far you step the motor that you have a 95 step overhead before reaching the goal. 50 steps to get off the home sensor actually requires 145 steps. A full cut at 630 steps requires 725, and a partial cut at 544 requires 639. This would seem to rule out slippage and missed steps since those would be somewhat proportional to the number of steps commanded. This is also the sum total of information you have provided. Without looking at your code, without knowing how the motor is being driven (your circuit or circuit provided by device), without knowing if the motor is unipolar or bipolar, it becomes very difficult to help you with your problem.
It appears that your code is somehow generating the first 95 steps that are either not getting to the motor or possibly those steps are not changing the coil sequence. A look at your code would certainly let us better help you.