Can you run a trace inside that function to verify data?
e.g.:
function uploadTest()
{
trace("upSpeeds: " + upSpeeds); // see what the function sees
if (int(upSpeeds) > 256)
{
upPass.visible = true;
}
else
{
upFail.visible = true;
}
}
Typically you may see the text is correct but if the variable wasn't defined in a global scope it is not available to the function and it will trace this to output:
upSpeeds: undefined
If that's the case you know upSpeeds needs to be defined on a global level so it can be utilized in that function.
. Trace often if you can, it's a very simple tool to debug. 
