What will really make your day is when RS Linx grabs the COM PORT 1 and calls itself AB/PIC COM1. Then if RS Linx doesn't release the COM1 port back to the computer, you can't use COM1 for anything because AB owns the whole COM1 port.
Generally I start RS Linx up again, then shut it down again. Normally the second time I start and close RS Linx, then it frees up the COM1 port again. Also generally I monitor CONTROL PANEL > SYSTEM > DEVICE MANAGER > PORT&LPT to see what the status of the COM1 port is.
Also to go along with everyone else, I click "continue away" but I do have problem in XP with RS Linx not letting go of the com port even after I close the application. I am running a DELL D800 with XP Pro and SP1 just in case you guys wanted to know.
Other than keeping an eye on the PORT HOG, I haven't see the other two windows either...