Reason for erase to stop working on AT89S52

I can't figure it out. For about a week I used the exact same software and exact same computer to program AT89S52 chips via parallel port and everything was fine until now where I plugged in a brand new unprogrammed chip into my programmer and did the same operations as I did with the other chips.

Now the problem is when i validated that space is erased, validation does not go past random percentages.

I double-checked for loose cabling but that didnt solve the issue.

How much time are you going to spend on a home made programmer??? You wastage really can't be worth the effort.

This guy Did it with 7 resistors and a couple of caps... And the PC software!!!

I'm starting to blame my computer. As soon as I globally disabled ACPI in the linux kernel, everything worked faster and so did my programmer. Only caveat I have to deal with is that my computer wont automatically shut off when its time to shutdown.