breadboarding

[mpgmike]

reset/mclr pin no pullup?

...or possibly Watchdog Timer nipping your butt. Somehow it sounds like you are getting a Reset condition, or maybe a Brown-Out. Check your VDD supply voltage when it quits. If it isn't what you want (especially if it's below about 2.5 volts), you are getting a Brown-Out Reset Hold condition.

You should have a 4.7k (up to 10k) pull-up resistor on MCLR to prevent inadvertent hardware Reset. In your CONFIGs, turn WDT (Watchdog Timer) off. You can do this at program time with PBP.

Since it works on the Dev Board, you have something (or lack something) not the same as the Dev Board. Do you have a capacitor on the power supply to your PIC? Data sheets suggest a 0.1 uF cap RIGHT AT your VDD-to-VSS pins.

Hope this points you in the right direction.

[dw_picbasic]

I agree to all of the above responses.
And I do very carefully ohm out all of the connections on a bread board before inserting a chip and before power-up.
Its not uncommon to forget something or get something wired wrong.

[towlerg]

Plugin breadboards suck, they are more trouble than the time they save. Make a PCB (or stripboard) with your goto PIC device and add stuff you want to try out on daughter boards, kinda like the boards Mikro Click boards. Often you'll find if your using things on breakout boards (thank you again Arduino for the super cheap modules) you just need a bit of stripboard and a connector.