RhinoFish - 5:11 pm on Nov 2, 2012 (gmt 0)
if you're appending data pairs, you need to add the "?" and "&" to your urls.
if you're dynamically creating landing page URLs, they're not URL data pairs, so construct them normally without those characters (but there are special cases where your URLs might have appended data pairs in their construction).
Using dynamic tracking URLs