just got a margincall, page-6

Some brokers mark CNP and CER to market pre-TH and use this in margin call calculations. Others have a different way of marking to market during a TH, which may give a distorted valuation to your portfolio.

It is probably worth ringing your broker to clarify. If they are edgy, or you get someone who isn't quite on the ball you may find they liquidate other positions you have. The other danger is that they may liquidate your CNP / CER position as soon as the market opens. The reason I suggest this is that I know of someone (not in the investment business) who had a problem when AFG went into suspension. A well known margin lender sold off some ANZ shares to cover the call, which IMO was a questionable act at best.