StrStr different behaviour

[jpc]

while converting some existing P18 code to P30 i found some undocumented difference in the behaviour of StrStr() function. According to the help ( identical in both) the prototype is : function strstr(var s1, s2 : string[100]) : word; On PIC this does not allow s1 to be in ROM so i made an equivalent search on match in ROM by using a Const-pointer . On P30 however, this seems to result in some trap , resulting in a reset so merely out of curiosity i checked StrStr() there and to my surprise it works ok. Can someone explain to me the difference in memory-access, i presume this will also be valid for other functions using var-parameters.
If legal it should be updated in the help.