They work as they do in PHP3. Please provide some test cases (i.e. it should output x, but outputs y)

a simple one for ereg_replace :

echo ereg_replace("\{FOO\}",1,"testtest{FOO}testtest");

does not output testtest1testtest, but testtest.garbagechar.testtest

but echo ereg_replace("\{FOO\}","1","testtest{FOO}testtest");
works normally.

As for str_replace I did not find a test case. This is a quite complex script
and I can't provide it to the mailing list . Here is a bit of the code :

      for ($j=0;$j<count($Templates["ParseVars"][$Name]);$j++)
	{
	  $ToReplace = strtoupper($Templates["ParseVars"][$Name][$j]);
	  $Val = $Vals[strtoupper($ToReplace)];
	  $Content = str_replace("{$ToReplace}",$Val,$Content);
	}

In PHP for example $Content ouputs :
BEFORE
"NOM_CAT" -> "Web Tools"
{CAT_LIEN}{NOM_CAT}

AFTER     {CAT_LIEN}Web Tools

With PHP4 :
BEFORE
"NOM_CAT" ->  "Web Tools"
{CAT_LIEN}{NOM_CAT}

AFTER     {CAT_LIEN}{Web Tools} 

I tried to put some strings directly in the varaibles but the function behaved
normally, so perhaps the problem is more complex.

I can provide the code to a PHP developper directly, but it's not commented
and all variables names are french, so it won't be easy to read. Feel free to ask
anyway.

1. ereg_replace is intended to work like that. Please read the documentation
2. str_replace should work now (CVS version)