I have all three expansions. I made my household in Bridgeport and my female character quickly rose to fame. Through receiving (and selling) several Margaret Vaguester cars (as gifts from the manufacturer) I amassed a net worth of over §600,000 - I then moved in another sim (who was a band mate with my original character) and renovated my apartment. When I thought that my original sim should settle down; I made a second family and selected them as the active household (so that I could build up their wealth and skills.
When I had built up some money and skills; I had the two sims get married, and because YOU HAVE TO have two newlyweds living together, I moved the female into my new active household. The problem is, she didn't bring the §600,000 with her. And here''s where it gets worse; I checked the apartment which my female used to live in (because her room mate was still there) and the §600,000 was nowhere to be found. I have two households and I'm missing §600,000!

this is where familyfunds or motherlode cheat comes in handy. Don't stress, just give them their dough back and you're set.

You took the words right out of my mouth!
It's really not that big of a glitch.