First I want to say that ESRI Support is working on this and will likely log a bug but also encouraged me to reach out here. This question is similar to the one logged by the poor user who submitted their question here that never got answered.
Server is version 10.2.1 and ArcPad is version 10.2.2 Very basic cached map service for testing. Service is consumed fine in Desktop (SOAP) and REST endpoint. Accessing map services from AGS via ArcPad first yields an HTTP error 400; then after clearing that error the icon spins and the service never loads. Adding map services from AGO or Bing images yields an HTTP error 400, but then the data does indeed load. Feature services can be added from AGS [but are not rendered as defined by their related map service component].
Please keep in mind that is is advertised functionality:
"
ArcGIS Server
Similarly to ArcGIS Online, you can configure your own ArcGIS Server to publish map services. Map services can be used in ArcPad in the same way as the ArcGIS Online basemap services. As with ArcGIS Online services, when you connect to an ArcGIS Server service from ArcPad a NMF file is created and added to ArcPad. Once created, this file can be added to future ArcPad maps, via the Add Layer(s) tool."
ESRI is able to replicate the identical issue; troubling since this functionality was released some time ago. Has anyone else experienced this behavior?
I will edit and post the NIM number when I receive it.