Can't help, but I can commiserate. I was just whining about this
happening yesterday. We're using PICSTART Plus, also. Funny thing
is, of three 877s on my desk, this is the only one to behave
like this. Now, with the good ones, I did get a lot of "Cannot
Transmit" Cannot Receive", etc. but they still take the bits.
This particular specimen took the bits once just fine, then suddenly
began reporting failure after finishing address 1FFF. A read
indicates that the original successful (but buggy) code is still
there.

 >
 > Just a quick note in case this jogs anyone's memory:
 >
 > I'm trying to program a PIC16F877 on my board, it's a TQFP package, I
 > have a 5X2 pin header for programming, identical setup to my
 > last project
 > using a 16F84 (jumpered for operation).
 >
 > I built a programming cable with a 40 pin socket on one end and a 5X1
 > plug for the header on the other, I'm using a Picstart+.
 > Again, this is
 > the same way I did it for the 16f84.
 >
 > 16F877s in a DIP package program just fine in the Picstart,
 > but when I
 > plug in the cable and plug that into a board I can't get it
 > to program, I
 > get various errors, including "Cannot Transmit", "Cannot
 > Receive", just
 > plain "Failure" in the program/verify window, and
 > occasionally something
 > like "Command 8F not echoed properly (F8)".
 >
 > Does anyone have any clue what might be wrong? Or
 > suggestions on what to
 > look for? The cable checks out fine with the ohmmeter, it's about 8
 > inches long and shielded, so should be electrically fine.
 > I'm stumped.
 >
 > Dave Johnson
 >