Hi Ceefna, and sorry to hear you have troubles with that board.
Hmm, it's hard to offer any decent help based on a few sketchy symptoms. I'm not familiar with that product at all but I can see it has two(!) PIC microcontrollers. That means a weird symptom set can not easily be used to diagnose the fault.
In other words, if the micros go to do something and they sense there is a fault they will cause the symptom set, or delays or weird behaviour etc. If the circuit was just a couple of logic chips the symptoms would tell you a lot more.
In the situation that you don't have a lot of test gear or good knowlege of the board, it might be easier to do some chip replacement. Basically you could replace the L293 and 74HC240 (and maybe the other logic chips?), and if that fixes it, fine. If not it might be a damaged PIC?
Sorry I can't offer more help, but its not easy to diagnose microcontroller product faults based on symptoms, and a fault that occurred after a bad short makes it even harder as you can't predict a "standard" failure.