Unfortunately, the answers and questions raised have not resolved the problem. Out local distributor Solid Sate Supplies has been unable to assist
Just to answer your question about responsiveness, yes,after the timeout message, telnet into a shell is very slow to respond. Rebooting restores a normal response. Perhaps the problem is with the vsftpd on the module which is obviously still running but perhaps is causing the problem. I will try killing this process. telnet could also be responsible, and since these are both part of the rootfs, rather than the kernel, they presumably may have been changed much later than the kernel date/time stamp. Also rootfs changes are much more 'manual' so it is easy to break something. I believe the rootfs uses prebuilt binaries, unlike the kernel.
Put simply - take a new clean install of version 5.7.0 Digi ESP. accept the package manager updates to 5.7.1 and then 5.7.2 as you previously said was necessary.
Create a Uboot/kernel/rootfs project and just accept the defaults. Configure the NFS/TFTPBOOT directories. Install the resultant image and then try to flash using the GUI. It fails after downloading the image with a timeout message. However, it will dboot from this tftp image.
After the kernel file has ftp downloaded to the /tmp direcory, it is possible to telnet into the module and run the flash_update filename partition succesfully. The module will then boot this from flash. The problem is therefore with the GUI section of the IDE, which is presumably invoking the same software, but the module is not responding as expected.
I have provided a lot of detail. Everything is stock, with no attempt to change parameters. It is clear that after the ftp download, the module is in a state where it responds so slowly that the GUI application times out.
I was prepared to buy a complete new development board and install it onto a virgin PC to repeat the test, but no hardware was available - since the JumpStart kit appears to be EOL. I also suspect that the JTAG version supplied with the baJumpstart kit may have a different version of Linux loaded.
Since manually running flash_update allows us to continue to use the module, we can proceed, but I am unhappy that the loaded version of Linux has been changed, obviously without proper testing with the ESP. This change appears to have taken place some time in 2014.
I provided details of the serial numbers of units which would flash, and those which wouldn't, but Solid State Supplies could not reconcile these with changes made by Digi.
I suspect these changes are to do with 'Discovery' and iDigi but this does not apply to the Digi ESP which does not use windows. I was asked to run the discovery application, but this request indicates the unfamiliarity with the Digi ESP system that our local distributor has.
Hope this helps to resolve the problem