The VFX company LookFX went out of business a few weeks ago. You may have heard that they lost a ton of money on the film Noah. The former employees of Look wrote an open letter that they sent to VFX Solder to post on his blog. It tells a fairly common story in VFX about workers who stayed loyal to a failing company and are now owed money that they will likely never see. One of the owners of LookFX responded to the letter here. It’s interesting reading.
If you find yourself in the situation where your company doesn't pay you one week, you need to find out if it’s a one-time thing (like your company switched banks, something technical got messed up but you'll be paid in a day or two) or a sign of something bigger.
If you get the feeling that this is a symptom of something bigger and it’s not a one time thing, then you need to find a new job in a hurry. I would recommend that you immediately stop working and leave the company.
Missing payroll can be a sign of serious, serious cash flow problems with the company. If your company consistently misses payroll, it’s likely that they’re very close to going out of business. When a company goes out of business, their assets get seized and auctioned off with the profits going to the largest creditor. Employees are unsecured creditors, which mean that they will likely get nothing or a fraction of the money they are owed.
The Globe has (much more level headed) advice on this subject. I might be a bit reactionary due to previous circumstances.