httpd eats processor

hi there, it's me again

    i wrote a library.
there are about 30 classes,  each has less then five fields, some
methods...

there are such a configurations of usage of these classes, that AFTAER
my php page is processed, the 'httpd' process eats all processor (httpd
hungs up) and it's hunging till i kill it.
i noticed, that when i'm changing the reference usage (in some places i
add and remove '&') i can control the problem (i mean, httpd doesn't
hung up)
but this is not a solution -> i never know if my next usage of class
will couse error on httpd.

is this known problem ? or this happens only to me ??

please help me, becouse our big project will be based upon this classes
library :((

    dariusz malinowski