[nomadking]

The ERM problems happened at a time when speculators were picking on different currencies, one after the other. If the speculators can be sure of how they are all likely to react(ie buy or sell a currency), then they can make easy money. IIRC the head of the German central bank(Bundesbank) said that sterling should be devalued, the government said they wouldn't. The ever helpful BBC News said that whenever a government said a devaluation wouldn't happen, it did anyway. This was the signal for action by the speculators. The government didn't devalue sterling, the money markets did. The speculators could profit by selling sterling, therefore driving the price down and then once things had settled, because the price had gone done, buy more sterling for the currency they had moved to(eg Deutsch Marks).

So the ERM problems were unseen to an extent, whereas the Gold issues where obvious straight away.