***SOLVED: ok so after 1 more day of working I managed to solve the problem; apparently there was an error in the heightmap;
There was some weird issue in a side-road ditch: despite the very low water level (20/30 cm) the character started swimmning above ground whenever near it, very weird issue. So I deleted the ditch from the heightmap BMP, reprocessed it in L3dt and now all is good.... finally!!! :)
Quick intro: I have been working on my terrain for a few months so far without major problems, here is a couple screenshots to prove that it was working just fine untill 2 days ago: screenshot1
These are my terrain mapframe samplers
My problem is: since 2 days ago, without changing anything significant that I can think of, pboproject started taking forever to binarize; it normally would take around 10/15 minutes, now it just takes literally forever and never makes it to the end :(
After checking everything for the whole yesterday (I even reinstalled/updated Mikero's tools) I realized that inside the previous working terrain pbo's (backups) the wrp file was around 15 Mb in size, the new ones I export from TB are 65 Mb. Could that be the problem?
Terrain specs are the same as usual (checked the old wrp with eliteness to confirm), but the wrp file is x4 in size; could that be the reason pobproject gets stuck in the process? What could the reason be for this sudden size increase? Or am I missing something else?
I also tryed Addon BUilder which also gets stuck in the process.
Let me also add that I have noticed a variable output number of layers in different pbo's (from around 1k mask+sat images/rvmat's to 5k even if the terrain has the same specs, but that never gave me troubles so far).
Thanks very much for any help, I googled it and could not fine any support :(
Edit: pboproject now seems to move my \source folder to P:\.source while processing, preventing me to access the real \source folder in the meanwhile; this is definitely something that never occured before; hope this gives additional clues.
edit2:if I set the grid to 2048x2048 it works