One of the main problems with pop up blockers is that some web sites use legitimate pop up that includes desired content.
Windows from appearing because they can’t distinguish a non-advertising window from an advertising window.
M+ Online trading system consists of screens that are in pop up format e.g. download Active X cab files.
Therefore if blocking function is on, these pop ups will not be prompted. As a result you will not be able to download the cab files and perform online trading.