Incorrect Operating system error 112(There is not enough space on the disk.) -

MSsql server gives this error while there is 24 GB physical disk space available.
I think an bug.
I have a disk of 100 GB All the files together are 100 GB big, but an part is windows-nt compressed so the pysical disk space of these files is 77 GB.
I tried to increase the tempdb by hand, but still gives this message.
If I delete files from the disk I can increase the tempdb.Forgot to mention is SQL2000 sp2 on W2K server sp1sql