? Eclipse question... where did my classes go?

hi, i am using Eclipse and I ran the Project->rebuild all. When It completed all my classes had been deleted! What is going on? does anyone know? i am not THATworried because my java files are still intact, but it is a bit odd i think. Any advice? thanks!
[286 byte] By [pnandrusa] at [2007-10-1 5:28:03]
# 1
It deletes them all before making new class files
tjacobs01a at 2007-7-9 13:23:20 > top of Java-index,Archived Forums,Debugging Tools and Techniques...
# 2
otherwise, where's it going to put the new class files?
tjacobs01a at 2007-7-9 13:23:20 > top of Java-index,Archived Forums,Debugging Tools and Techniques...