Problem of a Line Disappearing in QB.EXE Version 4.50 Editor (43696)

SYMPTOMS

Under certain circumstances, a line of code can disappear in the QuickBasic Version 4.50 editor. Microsoft has isolated two sets of conditions (shown below) under which this problem occurs. Although the line of code is not visible on the screen, it has NOT been removed from the source code. It usually reappears after any of a variety of actions (for example, after a carriage return on any line).

MORE INFORMATION

Example 1

The following steps re-create the problem:

Generate a nonfatal error (for example, "Bad filename"), such as in the following example:

      ' this can be any line
      OPEN "com1:3" FOR RANDOM AS #1     'change baud from 3 to 300

Edit (correct) the highlighted line that has the error.
Go to the previous line and press ENTER. This causes the highlighting to incorrectly go to the previous line.
Enter a statement, such as a=1, that will bring up the dialog box that has the following message:
You will have to restart your program after this edit. Proceed anyway?
Choose either OK or Cancel, and the statement that originally caused the error will disappear from the edit screen.

Example 2

In the Microsoft QuickBasic Version 4.50 QB.EXE environment, performing the steps below causes some of the following code to disappear:

   REM DIM x as integer
   PRINT "BOO!"

Use F8 (single step) or F10 (procedure step) to move the statement pointer to the PRINT statement.
Remove the "REM" portion of the first line.
Press the DOWN ARROW key.