I have a locally mounted samba share,
fstab:
//<host>/pmuskovac /media/usershare cifs user=pmuskovac,noauto,_netdev,uid=1000,gid=1000 0 0

after mounting that in konsole, trying to copy a file into the usershare folder gives:
13:51:24 dolphin(9005)/libkonq^[[0;34m KonqOperations::doDrop^[[0m: dest: KUrl("file:///media/usershare")
13:51:24 dolphin(9005)/libkonq^[[0;34m KonqOperations::doDrop^[[0m: URL: KUrl("file:///tmp/baloo_4.13.1.orig.tar.xz")
13:51:24 dolphin(9005)/libkonq^[[0;34m KonqOperations::_addPluginActions^[[0m:
13:51:24 dolphin(9005)/kdecore (trader)^[[0;34m KMimeTypeTrader::query^[[0m: query for mimeType  "application/x-xz-compressed-tar" ,  "KonqDndPopupMenu/Plugin"  : returning  1  offers
13:51:24 dolphin(9005)/kdecore (KLibrary)^[[0;34m findLibraryInternal^[[0m: plugins should not have a 'lib' prefix: "libextracthere.so"
13:51:25 dolphin(9005)/kio (Scheduler)^[[0;34m KIO::SchedulerPrivate::doJob^[[0m: KIO::SimpleJob(0x41c64c0)
13:51:26 dolphin(9005)/kio (Scheduler)^[[0;34m KIO::SchedulerPrivate::jobFinished^[[0m: KIO::StatJob(0x41c64c0) KIO::Slave(0x3c09180)
13:51:26 dolphin(9005)/kio (Scheduler)^[[0;34m KIO::SchedulerPrivate::doJob^[[0m: KIO::SimpleJob(0x413c270)
13:51:26 dolphin(9005)/kio (Scheduler)^[[0;34m KIO::SchedulerPrivate::jobFinished^[[0m: KIO::StatJob(0x413c270) KIO::Slave(0x3c09180)
13:51:26 dolphin(9005)/kio (KIOJob)^[[0;34m KIO::CopyJobPrivate::statCurrentSrc^[[0m: Stating finished. To copy: 125920 , available: 0

and an error window telling me that there's no space left, which isn't true:
Filesystem                  1K-blocks      Used Available Use% Mounted on
//<host>/pmuskovac 476852232 106516572 346112892  24% /media/usershare

Reproducible: Always

Steps to Reproduce:
1. Mount a samba share from fstab/command line (not by using smb:// in dolphin, that actually works fine)
2. Copy a file into the mountpoint in dolphin
Actual Results:  
An error window comes up telling you that there's no space left

Expected Results:  
The file gets copied