Hi Tony,
This is often related to available memory on the machine, and sometimes related to the size of the print job - where the logo file is large.
One thing to try is using MS Paint or some similar application to re-size the logo file and make it smaller. Then insert the smaller logo into the specification. Remember that if you insert a large logo into a spec and shrink it there, the attached file size is still the same.
The invoice batch shouldn't have any influence on how logos print with specs. Something else is likely happening when batches/invoices are deleted and re-created.