> I has a UDF with works fine in Firebird 1.5 and crash the firebird
> server 2.0 with a access violation.

...

> char* st = (char*)malloc(1 + strlen(s) + countespecial(s));

...

> The sql register code:
> DECLARE EXTERNAL FUNCTION STRQUOTED
> CSTRING(256)
> RETURNS CSTRING(256) FREE_IT

You must use ib_util_malloc from ib_util.dll instead of RTL's malloc

Regards,
Vlad