Use opacity instead of filter if the browser is IE9 or higher

[nemeseri]

IE9 and IE10 are supporting the opacity css property. It would be better to use it instead of filters.
You might use -ms-filter if the browser is IE8, because the original filter property might cause issues.

[ded]

cool. I'll add a workaround as done the same as Morpheus

[mantoni]

+1 This is also an issue if the UserAgent string was changed - I had to do this with Chrome to get through a nasty proxy. Not an issue with the technique used by Morpheus.

[dcecile]

Using the MS filter caused problems in my code with IE9; the problem was fixed by editing Bonzo to use opacity instead.

Switching between opaque and transparent caused my div to become permanently transparent. I can provide a minimal example if needed.