an error of type -5016 has occurred

i have an apple script which runs when i first login to OS X. the problem is i get the above message and it wont mount my network shares. However if i leave it a few minutes longer it runs without any problems

the script im running is as follows

mount volume "smb://server/Data"

mount volume "smb://server/Public"

mount volume "smb://server/Software"

mount volume "smb://server/multimedia"

can anyone help