I have uploaded Ypsilon 0.9.5-update2. I guess this version successfully fixed some bugs. Ypsilon has covered 98.9% of PLT R6RS test suite which has been released recently. I really appreciate the great cooperation from many people. Thank you so much. 
Especially I’m pleased this time I could fix two concurrent GC bugs which are very hard to find. They were found in a test program called gcbench in R6RS Benchmards which Mr. William D Clinger kindly sent me. Many thanks to Mr. Scheme! 
Ypsilon 0.9.5-update2 is available at: http://code.google.com/p/ypsilon/ Currently MacOS X, Windows Vista, and Linux are supported.
-Fujita
