VM111 will not program a second time

I have just started using the VM111 PIC programmer with the supplied software. I have loaded the supplied example program demo1 into to 16F627 chip supplied and it worked ok. I then tried to download demo2 to the programmer but I got the error message “NO PIC ON BOARD, PROGRAMMER MUST BE SET TO PGM MODE, PIC TYPE MISMATCHED WITH SOFTWARE”. I then tried a brand new 16F628 chip and demo1 worked ok. I tried to download demo2 to the programmer and I get the same error message. I get the same message if I try to erase the program in either chop as well. I’m using windows XP. I am new to PIC programming, any ideas what I’m doing wrong ?

proably you are using the VPP line also as I/O.
Try not do do this because the PIC is not always swithable to programming mode.