Billing Contract -- Not all lines invoiced

Does anyone have ideas of what to look at if a given contract was invoiced but not all of the lines on the contract invoiced?  I have checked the billing schedule, dates and everything matches on the lines that billed correctly and those that did not invoice.  The program Service Contracts Main Billing has completed with a warning but it just tells me the number of lines that did not process but no detail.  I've checked the log file and have looked on metalink and I'm not able to come up with anything. 

Any help or advice on where to look would be greatly appreciated.