Earlier this year, an operating system update (6.7.16) was released for the Geo 7X handheld. Support cases submitted to both Trimble and Esri have indicated that ArcPad users with complex projects are running up against memory problems with increased frequency after upgrading their devices to this new OS version. Customer and dealer testing indicates that there is ~4MB less memory available to the application compared to the old OS version.
This issue is being investigated internally. Initial testing suggests that any high-memory use application could be affected including ArcPad and ArcGIS for Windows Mobile + Trimble Positions. At this time, it is recommended that Trimble Positions users with larger field projects stay at the previous operating system version (6.7.15) until further notice.