shared folder given the standard domain user account full ACL NTFS and share perm to the folder \\server\share....

Can't write into the share?

The user is using logon type 3 which network...

((I've never restricted standard users from locally logging into my servers it's just always worked that way, I've never seen a "deny local login" (as I've setup for my teacher stations))

Error in security log is:

An account failed to log on.

Security ID: NULL SID
Account Name: -
Account Domain: -
Logon ID: 0x0

Logon Type: 3

Account For Which Logon Failed:
Security ID: NULL SID
Account Name: frogbackup
Account Domain: DCC-SCH-4505

Failure Information:
Failure Reason: User not allowed to logon at this computer.
Status: 0xc000006e
Sub Status: 0xc0000070

Process Information:
Caller Process ID: 0x0
Caller Process Name: -

Network Information:
Workstation Name: \\
Source Network Address:
Source Port: 51392

Detailed Authentication Information:
Logon Process: NtLmSsp
Authentication Package: NTLM
Transited Services: -
Package Name (NTLM only): -
Key Length: 0