I had a bunch of issues with the same thing.
Ended up only restoring only my contacts and calender.
Found that after restoring everything my Bold would stutter or slowdown for no reason at all - Third party apps would sometimes act strange or crash.
Ended up wiping the device clean and restoring only contacts and calender.
Installed all third party apps from scratch (note: some third party apps have OS 4.6 versions and run better) and set up all BB settings again from scratch.
Now the Bold is amazing performance wise, i mean it is fast..
Heard about this from another post thread.
BB Bold 9700