Nima,
Are you on a 64 bit version of the JDK and 64 bit version of Helios? .
If not try having both on 64 bit, so that you can leverage your OS.
Also, edit your eclipse.ini
file to launch it pointing to a specific vm.
eg :
-vm
myjdk/1.6.0_22/bin/javaw.exe
[SOLVED] Issue resolved with deleting the .snap file from yourworkspace\.metadata\.plugins\org.eclipse.core.resources
Explanation for the snap file :
While Eclipse is running, information about what has changed in the
workspace is incrementally logged into various "snapshot" files
(including .snap). On normal Eclipse shutdown, the complete workspace
state is saved and the .snap files are deleted. When Eclipse crashes,
the snapshot files are used during the next startup to recover from the
crash.
So, it appears that some error is occuring that is causing Eclipse to
crash. Then, there is an error recovering from the crash on the next
startup. These are quite possibly unrelated problems, but by manually
deleting the snapshot file you are tricking Eclipse into thinking that a
crash did not occur, so the crash recovering routines do not run.
from http://www.eclipse.org/forums/index.php/mv/msg/39563/129039/#msg_129039