menion,
about the problem with updating cache coordinates, I tried the "Update cache" functionality in Locus on GC1C6P1 now again an it still does not work.
Then I tried the same with GC2F2D0, which already has updated coordinates in Locus (and its icon is marked with star) - its coordinates were not lost, they stayed corrected as they were. I deleted GC2F2D0 and downloaded it again using the Import GC functionality and it was correct, with corrected coordinates. Deleting GC1C6P1 an reimporting does not bring its corrected coordinates. Strange.
So I dug into the data that is downloaded from GC into Locus using Shark (and Wireshark) and I found the following difference:
For GC1C6P1, there are original AND corrected coordinates in the JSON, and for GC2F2D0 there are only corrected ones. I recall I mistakenly used the "Correct coordinates" feature for GC1C6P1 and entered the original coordinates, which then I reverted back by using Restore, and then entered the correct final coordinates - maybe that's why there are two of them in the output. Compare (output from Wireshark):
GC1C6P1:
"UserWaypoints":[{"CacheCode":"GC1C6P1","Description":"Coordinate Override","ID":3231097,"IsCorrectedCoordinate":false,"Latitude":49.16325,"Longitude":18.778467,"UTCDate":"/Date(1375635535977-0700)/","UserID":5884890},{"CacheCode":"GC1C6P1","Description":"Coordinate Override","ID":3237835,"IsCorrectedCoordinate":true,"Latitude":49.1543,"Longitude":18.811467,"UTCDate":"/Date(1375719794327-0700)/","UserID":5884890}]}],"PQCount":0,"CacheCodes":[],"CacheLimits":{"CachesLeft":5994,"CurrentCacheCount":6,"MaxCacheCount":6000}}
GC2F2D0:
"UserWaypoints":[{"CacheCode":"GC2F2D0","Description":"Coordinate Override","ID":2609483,"IsCorrectedCoordinate":true,"Latitude":49.173217,"Longitude":18.81005,"UTCDate":"/Date(1367657873907-0700)/","UserID":5884890}]}],"PQCount":0,"CacheCodes":[],"CacheLimits":{"CachesLeft":5993,"CurrentCacheCount":7,"MaxCacheCount":6000}}
It looks to me that Locus took the first "Coordinate override" regardless of its "IsCorrectedCoordinate" attribute being true or false.
Now I found another issue - I generated a pocket query for Zilina and near caches, imported this GPX into Locus and all my solved caches were at corrected coordinates, so far so good (including GC1C6P1). But they were not marked with star - and this is important because then in the field I don't know if the cache really is in that place or those are just the dummy coordinates. I know it worked OK not so long ago (a month?) so something must have gone wrong...