[Zope] CacheManager pb with zope 2.6.2 -> zope 2.7 ?

Hi, coming back to my HTTPCache Manager Problem (losing object association after restarting zope server). I wonder if i could use the zope 2.7b3.. is there a risk for the zopedb structure (let s say when i will retun to zope2.6.2) ? If it actually solves my problem, would you say zope2.7b3 is "stable" enough for me to use in a prod env. knowing my users are very few , or is it too risky ? Thanx in advance Seb