RC debouncer circuit does not work
Refering to the first circuit diagram:  

If \$V_A\$ stays too high when button is pressed, \$R_2\$ obviously is too large.

So you have to decrease \$R_2\$.

If that in turn decreases your time constant \$\tau=(R_1 + R_2)C\$ too much for the circuit to work properly (i.e. debounce properly) you have too increase \$R_1\$ and/or \$C\$ in addition.  

BTW: You wouldn't have this problem if you used CMOS logic (74HC04 or better  74HC14) which has very high impedance inputs (i.e. practically no current is coming from the input).