I have a problem with an SharePoint 2007 site where the navigation menu flyouts (drop downs) render as a blank white space. This problem only happens on our clients network. It works fine on my own machine/network.
It renders like this: http://i52.tinypic.com/2nrezq1.png
But it should render like this: http://i52.tinypic.com/2hzfhx.png
When I switch the masterpage being used back to the default blueband, the problem does not occur which made me think it is related to our custom masterpage. BUT if this is the case, then why would it work in IE8 on my machine/network. Ignoring the latter, i decided to remove all js from the master page, this did not fix it, then i removed the css, this didn't fix it, then i replaced the navigation items in our custom master with those from blueband (SharePoint:AspMenu ID="GlobalNav" and PublishingNavigation:PortalSiteMapDataSource) - this didn't work either. Everything else in the page is just pure markup, and hence should not be affected by network or environment settings (or should it?)
Also, I found this previous post which sounds similar and states it was fixed by changing company intranet settings - although I don't know what settings those were.
Does anyone have any suggestions?