Bump.... please help.

Sorry that you aren't getting any answers in this thread. I dropped out of this thread hoping that one of the Sync developers would pop in to help out in this thread, but being the holiday season the developers may be occupied with family life. I assume that they might have a "real life" outside of Mozilla and Firefox.

services.sync.engine.prefs.modified shows as "userset" and is bold for me when Sync shows as "Connected" in Options > Sync. When I Disconnect from Sync the state goes to "default" and the "bold" type is gone. Looks like that pref is the internal "toggle" pref for activate / deactivate via the Sign in to Sync and Disconnect... buttons in the UI.

That's all the new information that I have for you in this thread.

I have been using an extension - https://addons.mozilla.org/en-US/firefox/addon/config-descriptions/ - that adds the developer Source Comment for each pref so annotated in Firefox source code as installed (that is written in to the source code to explain the function of the pref) to a new column on the right-side of the about:config page. The current Sync 1.5 version which is used in Firefox 29-plus versions has far fewer Source Comments that the two previous versions of Sync had.

One of the reasons that I lost interest in "Sync" for intellectual / technical knowledge to provide support to other Firefox users. I did look at Sync 1.5 again when Add-on sync was added, but I became disenchanted further when I found out how little data, with regards to "add-ons" prefs and data was synchronized on my test Profiles last spring. Between the lack off documentation for Sync in general, lack of information that I could find about each add-on's individual sync prefs from add-on developers in their "About this Add-on" at AMO for their add-on, and the overwhelming number of sync prefs added for each add-on in total; I decided that "this dog ain't gonna be in my kennel, it will need too much training and attention"! No one wants a dog that defecates all over the place.  ;>)

I have one desktop PC (in use now) and no laptop or "mobile" devices; my pursuit of knowledge was done via multiple Profiles on the same 'device' in the past. Isn't something that I really need for my own use. Overall, with the lack of user documentation and developer documentation (collected in one "arena") provided by Mozilla on-line for Sync 1.5 and the lack of source comments in recent versions of Firefox, I curtailed my "pursuit" of additional Sync knowledge about 18 months ago.

Plus it doesn't help that the US Navy trained me to operate and repair vacuum-tube equipment used in carrier-based aircraft that was a decade "old" already when it was relegated to the Reserves, my college curricula for electronics and computer science was with punch-card computers that filled a room and needed their own HVAC systems; and my career (and eventual "degree" was automotive technology) was spent as a master automotive & truck technician / shop owner & operator which where I learned about PC's - to 'run' the front-end of the business beginning in the mid-1980's. The "costs" in those days made it cheaper for me to learn it and do it myself in the evening or on a weekend when hardware upgrading was involved. A couple of hours of a computer tech might eat up profit for an entire day. "We" had to learn & use a lot of DOS code before the days of Windows "Plug & Play" for peripheral devices and PC hardware additions or updated PCI cards. Basically I am a "fossil" by age in the modern world of PC's.

@the-edmeister

Thank you for replying. I hope one of the Sync developers will take a look at this issue after the holidays.

You're welcome. Have a nice holiday season.