sync error after registry tweak

[docebp]

Using Ipaq211 w/wm6 and vista WMDC 6.1, I changed max amount of text during sync from 5120 to 15360 to eliminate truncation of notes in mobile outlook. Performed soft reset. Kept encountering sync failure [unspecified] until I changed back to original 5120 in registry key. Did I miss something or is there some companion change that needs to be done? Can this value be changed successfully? Thanks