H-BRIDGE and DC-SERVO DRIVE improvement help!

Hi forum:

I had build the H-Bridge by looking at this following
design:

http://cet.ssu.portsmouth.oh.us/~jlindeman/h-bridge/hbridge.html

This above design uses PNP and NPN DARLINTON BJTS TIP12X series in
its
design. This design works ok as far as the switching frequesny
applied is no more than 3~4Khz. I had put it in an application where
the PWM freqyncy is 11.7KHz. at high frequenies this design fails,
burning transistors.
I had tested this desin in my lab and i found that when you drive the
left PNP darlinton and the right NPN darlinton by appliying the PWM
signal at left side then the right side PNP darlinton starts getting
heat up, when the PWM frequency is 10~20Khz, and eventually the right
side PNP darlinton blasts!!
It seems the the right side PNP darlinton recieves the driving pulses
when it should not get driven. since in an hbridge at a single moment
there only two transistors should conduct, and in my case 3
transitors starts conducting which causes so much high current
through the transitor.
same happens when i apply the PWM signal at right hand side, but this
time the left side PNP darlinton starts getting heatup

I had also tried MJ11032(NPN) AND MJ11033(PNP) darlinton high speed
switch transistors(specially designed for hi amp inductive load
swithching) with 50AMP continuos current capability in my
circuit. but observations were the same.
I need to design a professional dc-servo drive which can operate upto
80V and can deleiver around 20-30AMP.

please suggest what changes should i made in this schematic so that
i can use this H-BRIDGE design for HI frequency PWM signals and for
hi amp loads !
i request everyone to please suggest me any designs and or links
best regards
@sim