vsftp quitting after few uploads

I am running a vsftp server for two network cameras that upload a picture every hour. It works fine for 5 to 7 uploads and than it just quits:
<-Begin xferlog->
Sun Feb 14 19:42:18 2010 1 192.168.1.32 341544 /home/ecam/image_100214_144205.jpg b _ i r ecam ftp 0 * c
Sun Feb 14 19:50:13 2010 1 192.168.1.31 264396 /home/bcam/image_100214_145012.jpg b _ i r bcam ftp 0 * c
Sun Feb 14 20:42:18 2010 1 192.168.1.32 340657 /home/ecam/image_100214_154205.jpg b _ i r ecam ftp 0 * c
Sun Feb 14 20:50:13 2010 1 192.168.1.31 259144 /home/bcam/image_100214_155012.jpg b _ i r bcam ftp 0 * c
Sun Feb 14 21:42:18 2010 1 192.168.1.32 347070 /home/ecam/image_100214_164205.jpg b _ i r ecam ftp 0 * c
Sun Feb 14 21:50:13 2010 1 192.168.1.31 267066 /home/bcam/image_100214_165012.jpg b _ i r bcam ftp 0 * c
Sun Feb 14 22:42:18 2010 1 192.168.1.32 352610 /home/ecam/image_100214_174205.jpg b _ i r ecam ftp 0 * c
Sun Feb 14 22:50:13 2010 1 192.168.1.31 367278 /home/bcam/image_100214_175012.jpg b _ i r bcam ftp 0 * c
Sun Feb 14 23:42:19 2010 1 192.168.1.32 0 /home/ecam/status b _ i r ecam ftp 0 * c
Sun Feb 14 23:50:14 2010 1 192.168.1.31 0 /home/bcam/status b _ i r bcam ftp 0 * c
<-End xferlog->
If I reboot the server it will work again for some time and than stop again. Anyone seen this before?
Best
Axel

 

Maybe this has something to do with quota? What's the output of

Code:

repquota -avug

?