There are several things that might be wrong
You may be over your disk quota.
To check this, you can either remotely access csil.cs.ucsb.edu via SSH or enter CTRL + ALT + F3 at any Linux machine. This will bring up a non-graphical login prompt. After logging in here you can then use "quota -v" to get a high-level look at where you stand.
[Queequeg@pequod]$ quota -v Disk quotas for user Queequeg (uid 19041): Filesystem blocks quota limit grace files quota limit grace frigga:/local/home/student 12253 50000 55000 4195 10000 13500
You can see that Queequeg is using 12253 blocks of his 55000 limit. He"ll receive a warning when he goes over 50000 blocks. It"s a good idea to watch your file limit also.
To see your 10 largest files, use du -sk * .??* | sort -rn | head
And remember to purge your browser cache from time to time.
Your password may be expired.