silverlight

I can not get Silverlight 5 to run..On Netflix it keeps asking me to instal it. I have had to remove it several times manually using Microsot's instruction they send me via email...Also tried to go back to 4 runtime but Netflix and my computer won't run Silverlight. Just started happening... Microsoft has no clue. They are telling me it's a problem with my iMac...Lion 10.7.2 intel i7 8Gb ram..SURE!!! Any one have a fix?

Wont run on Safari or Firefox