I am using a Trimble Nomad 800 running ArcPad 10, and have been perplexed at why a project that ran fine on a Trimble Recon under ArcPAD 7 worked fine but under ArcPAD 10 was plagued with the Low Memory warnning. I turned off all Extensions, I even turned off all background rasters(TIFF's) and still with just a dozen or so Shapfile on if I ran the GPS within 10 min the Low Memory warning would show up and If I wasn't paying attention eventually ArcPAD crashed and closed. SO finally I just stopped using the GPS unless I was collecting data. Then the otherday I was eating lunch (in the field) and was panning around and reilized I had (6) Text points in a Graphics layer I didn't need any more (the only six features in the Grahpic's Layer) so I deleted them. Yesterday back out in the field started the project turned on the GPS to get the map in the general area I was working and forgot to check on it, well 30 mins later I looked and the Map is panning with me and no Low Memory message after 3 hours things are still fine, I turn on (1) 2.5 meg TIFF and still no issues. Eventually I turned on all 5 TIFF's (background images) and at the end of the day still no Low Memory message.
So APG layers can be useful for taking notes but I am going to rethink the use!