Impossible to modify files on Linux (Kubuntu)

[brokic]

I just set up 2 MB WE on a client that uses kubuntu as its main os. The problem is that when they are using linux they cant modify the files that are on the MB WE, I in fact can create files, but Im unable to modify them. Using Windows XP in my laptop I can create and modify files just fine. What am I doing wrong?