I have also been running Geoserver on JRE7.
I have two installs of Geoserver running on JRE7 (JRE_1.7.09-b05): GS 2.0.2 installed on Win2008Srvr and GS 2.2.2 deployed in Tomcat on Win2008Srvr. Both are 64bit JVMs.
Maybe the issue is with the new Geoserver versions, the later JRE7 versions, the 32bit JRE versions or your individual install or setup. Still lots to check - I'd start at reverting to the older JRE7 version.
Abe.