What interesting timing .. I just went through an 'interesting' couple of months fighting this exact problem.
The exact symptoms as you describe, seemingly random layout elements missing from the print, both fields and layout objects. The primary print script in question does a invoice batch print, first an office copy, then a customer copy, next record and repeat, but the issue would also manifest on other single copy print jobs if they were scripted with no printer dialog. Our first hard clue was when things were printing fine from a Win7 32bit machine and then an operator printed the same job from a Win7 64bit, every other page was messed up. Switched back to the 32bit machine and the next print job had errors, but then it was OK (mostly). Tried the 32bit Win7 for several days and things were better but still random pages with errors. A quick check found that the last Windows version FM8 was certified for was Win XPsp2. Our solution was to setup an XP machine on a dedicated printer for all the big print jobs, and it has printed with no errors for 3 weeks now. Other small print jobs from Win7 32 and 64 bit to different printers still have the random error, but they have decided they can live with that. As long as no Win 7 machine prints to the XP's printer things are good. Hope this helps, YMMV.