Ugrading Program from D4 to D5

Hi All,

I trying to recompile a app written in D4 that calls D3 written DLLs, the
app compiles fine in D5 but when run it crashes with application errors at
the point of calling functions/procedures from the DLLs, any reason for
this.......is there a switch I can use to tell D5 to use DLLs in the same
way as D4.....I need this to work, no way of changing the D3 written DLLs

Any ideas

Please reply to the group and private....

Many Thanks
John Staples