I think it's just the poor performance of snapping. Heck, even smart guides are often "off" by a few pixels. 

If you click-drag on the end anchor point you'll have better luck with it snapping to the intersection. Snapping is often dependent upon the position of the cursor.

However, Smart Guides will never show that intersection. Honestly.... bug in Illustrator. Snapping/Smart Guides have been pretty bad the last few versions.

Illustrator, snap to guide


The circuit shows an IR receiver whose output pin is interfaced with a PIC. Can you explain why a resistor and capacitor were used and why those values were picked.
