TC51 compatibility with 6.7

Hello,

   We are currently using version 6.6 of the EMDK. We have few TC51's out in the field and we are in the process of migrating to TC20's. On the release page, version 6.7 shows compatibility for TC20, which prompted us to update. Unfortunately, the app started to crash on TC51 with version 6.7 emdk libr, are there any known issues with the new build? Version 6.6 seems to work fine with TC20's even though it is not listed, are there any known issues staying with 6.6?