Kernels earlier than 3.3.x have many bugs.

The following are just examples of those:
 - Some kernels need exactly ext3 fs to boot
 - Some kernels has errors from glibc, need patch. "getline error",
 - Current Debian stable does not support kernels before 3.2
 - Error from m4 package, need patch. "freadahead.c error"
 - Error from ttyS0 at boot
 - Some kernels get stuck at "booting kernel"
 - Some kernels get stuck elsewhere
 - Network might fail even it has been tested working for later kernels
 - Package "inet" might fail at boot. "if_index.os error"