If you copy data that looks like it is a delimited set of data Excel
sometimes does what I think you're describing. If you are copying a single
enter the solution is to select the target cell and then put you cursor on
the Formula Bar and paste.
Earlier you ran a text to columns (manually or in code) and it remembers the
settings you used.
To make excel forget your settings:
#1. You can close excel and reopen it (yechhh!)
#2. You can do a dummy text to columns.
pick an empty cell
type something into it
do the text to columns
Use delimited, but uncheck all the options
finish up that wizard
and clean up this cell's contents.