There was a thread about this recently - have a quick look for it.
Basically, the decision was that any hypo symtoms you get with a BG level of OVER 4, is a FALSE hypo.
Sounds like your system just needs to re adjust to the lower (better!) BG levels that you are now able to maintain.
We also discussed experiencing hypo systems after a big drop in BG that maintained your BG level above 4. The theory their, is that hypo symptoms manifest themselves at relative, and absolute levels.
That is:
hypo at anything below 4 = absolute
hypo when there's a big drop but leel remains above 4 = relative. (relative to the drop in bg, and not the level that it drops to).
For me, I wouldn't treat a hypo at 6.5, unless I knew I wouldn't be eating in the next few hours. The problem with treating hypos, is getting into that feedback loop of treating the low blood sugar, increasing dose to cover the high BG, going low again, treating again, dosing again and so on...