mysql 3.22.21 on linux seems incompatible with functions/mysql.c from 3.0.8 and up..
if I take mysql.c from 3.0.7 and put it in 3.0.9 tree, no problem.
if I try the 3.0.9, when mysql_connect() is succcessful here is what i get in the logs:
Block 0x084208D0 status at variables.c:77:
Beginning:      Cached (allocated on functions/string.c:1318, 5 bytes)
      End:      OK
---------------------------------------
---------------------------------------
Block 0x08421908 status at variables.c:77:
Beginning:      Overrun (magic=0x4011A648, expected=0x7312F8DC)
      End:      Unknown
if it's not successful, i get proper error messages.