if acid mentions function names in the 'reports' of allocated or free  blocks,
remember them such that leak can show them:

% leak  399373
block 0x0001cc20 0x00000040 0x0000a7ef 0x00000000 fmtstrinit+0x38 0x0
block 0x0001e4a8 0x000000a0 0x0000102f 0x00000000 emalloc+0xf 0x0
%

(if this is too expensive memory-wise, would a string 'allocater' that
 stores each unique string only once help?)

Axel.