Error msg... Error: Could not open lock file (/home/..../photos.dat.lock) for writing!

Hey folks!

I had the problem with "Error, your userfile is not writeable", which i fixed by chmodding a specified directory and its content to 777. Now i can see my album, but when i enter into any pictures folder/album it says:

Error: Could not open lock file (/home/samobnet/public_html/albums/julbak07/photos.dat.lock) for writing!

I have chmodded some of the files that the message refers to to 666 (which should be enough for writing (?)) but the msg still appears when entering into the folder. It seems possible to view pics, but something is apparently still wrong. The msg does disappear after entered the picture once, the second time the msg is not there. Seems like the error msg is just annoying, since it disappears by itself.

My questions are:
*Is there a way one can make the message disappear without scrolling through all pics?
*What does the error msg mean?'
*What chmod setting should the referred file have?

My adress to the site is www.samob.net

Greatful for help, thx!

/S