Looks like some special problem.
1.You wont tell whether hardware or program coding problem
2. You wont like to post your diagram
3. You wont tell how you got problem solved.
So one can wonder whether you had problem or not!
I guess that once I had this type poblem with 20x4 LCD.
I would display entire string of characters with just start
address pointer and display routine would check "end of string"
character and stop there. In one string I forgot to put
"end of string" character so the display would show characters
for all contents in data ram. So it would contain alongwith
blank spaces all cursors and grafic characters.
May be before ending thread you can put out your solution ,
so that some newbies may benifit without posting.