I'll be happy to oblige:
EDIT: Erik edited more details in while I was writing this message, I'll reconsider and perhaps edit in turn...
What's your second way to read that?
EDIT #2: Alright, I do understand the different meanings you propose... interesting confusion, can't reply anything else to that right now!
Given that you have made me realize in the last few messages how I may have missed language subtleties in rule descriptions (English second language here), I am now wary of taking my understandings for granted, hence I may sound really obtuse or anal in this next section:
... that other entry could also be read as maintaining a spell, while maintaining another spell. My point was that it is still unclear what the "continuing situations" subtitle of the table applies to. We're supposed to have a section in the table for conditions applying only to ability to maintain a spell... I can't see where ELSE that section might be, even though if we consider the table without the accompanying paragraph I would most certainly read it like you: as more conditions applying directly to casting a spell, or with -3 to target levels, to maintaining a spell.
That's how I've always read it as well. In fact, the entry provides a +3 modifier "for each spell beyond the second", which strongly suggests that it's about maintaining a spell while maintaining another. Also the text in the same page is very clear about the fact that some actions are possible while maintaining a spell, but impossible while casting it; it seems to me that casting a second spell simultaneously must be one of these impossible actions, or virtually every other action would be possible.
I would also point out that, from the description of Boreal Flames, I had never imagined it was meant as an example of a spell that may be cast simultaneously with another non-fast cast spell by the same caster. I've always stuck fast to the rule "one spell per round, with fast cast spells not counting against the limit", which is also the interpretation you get from the much clearer combat rules in Lords of Men. Violating it messes things up horribly.
Finally, I would point out that I am another one of the people with gripes about MoH. I've never got to listing them all in one place (though I may), but I really do think that it was a book that opened more cans of worms than it closed. This of Boreal Flames is one more I've just added to my list. I found MoH moderately interesting, but in terms of mechanics a far cry from the usually high standards of Arm5. Sorry.