just wanted to drop some code again. Sry, still no git :\
That small modification makes you jump to the next block of changes (with CTRL+UP/DOWN).
I was also wondering, what happens to "Synchronize Horizontal Scrolling" after/while comparing. Then I found the typo in your code:
In "startCompare()" function you're using 2 IF-conditions with IDM_VIEW_SYNSCROLLV, but in the second one you should use IDM_VIEW_SYNSCROLLH instead.. and everything's fine again :)
that link is dead, can you upload it again ?