Zero-Cross detector problem
Resistor

A 150k&Omega; resistor on 220Vac is dissipating 0.32W and probably should be burning up.

A 330k&Omega; resistor on 220Vac is dissipating 0.147W, which is in the rated range.

As one of the commenters suggested, your math of 10x higher is a bit off.  Maybe you should try a 330k&Omega; resistor?

Interrupts

Don't tell us the interrupt durations, show us the scope capture of the node on pin 5.  If the scope capture checks out, then you know it is a firmware problem and you are describing a hardware problem.  Please ensure that you have a hardware problem before describing it in terms of software.

Just speculating without a scope capture, but it could be that your pull-up is too strong?  You have a lower resistance than the other.  Maybe try a 10k?  20k?  Again, post a scope capture.