Target Machine Printing Error Message

I have facing a problem with using the VB.net and crystal report. I have designed an application at the XP platform which included the crystal report to the application. At the XP platform the crystal report seems run smoothly, so i made a setup file. The problem is that when i setup the application to the target machine which is using the Win98 OS and crystal report seems no problem at all, but when i clicked the "Print" button on my target machine, one of the message shown. The message shown as "Object Reference is not set as an instance of an Object" and the print process is terminated. I just want to know what's the Problem?

I hope they are someone can help me !
thank you