I've never gotten a really good SWR reading on my HT antennas when using the Surecom SW-102 for the reasons already mentioned. I do get good SWR reading when I use my Comet CA-500 antenna analyzer though. The Comet is bigger than HT's with a nice flat surface where the antennas mount. But I still get higher SWR readings on some HT antennas with the Comet analyzer yet they work just fine when attached to the radios.
As others have said, don't rely on testing HT antennas for SWR, you can get misleading results.