Um, don't open the film box unless it is in the dark? It wasn't clear (to me) if the original poster had sheet film experience of any sort.
You'd think that goes without saying, except that the amount of times I've seen an open box on fleabay makes it worth saying still. Depending on what brand you buy, some have double-box, some triple-box, some fold-over and stick a black bag, some are sealed when you buy them.
Always worth opening in a dark bag/room (and that's kind of mndatory to load them into holders, of course).
FWIW, I've got a Mod54 and it's great. The only time I've had film 'pop out' was actually doing 9x12s and I completely overagitated (well, rolled) when I was washing them, the film got caught between the edge and the plastic and scratched all the emulsion off. A mistake I won't make again.
The only reason that I don't use my Mod54 much anymore (I really should sell it) is because now I've got a Jobo 2509n.