SMB File Share visible, but cannot be accessed.

I have a network with 2 laptops running Windows 7 and my IMac running SMB sharing across the network. This was working okay, but the network speeds were slow (1Mbps). I changed my router settings to 802.11g only, and the network speed has improved (10Mbps), but now the PCs can no longer access the IMac share folders. The IMac appears in the windows explorer, but whenever I try to connect to it, I am presented with an error that: "You might not have permission to use this network resource" or "The network path cannot be found." or "The spcefied name no longer exists." The error messages appear differently no matter if I try to access the computer by clicking on the icon in explorer, typing \\<ip> or \\<name> in the run dialog.

I double checked my settings on the IMAC. sharing is checked, a couple of folders are set up as a share. Under options SMB is checked. In User Account settings, in the Guest user the checkbox for "Allow guests to connect to this computer" is checked. This is the setup I had before changing the network protocl from "mixed" to "G only".

looking at the samba logs in console, I found some, perhaps, interesting log entries.

log.nmdb

*****
Samba name server BLAKESIMAC is now a local master browser for WORKGROUP on subnet 192.168.15.100
*****
[2012/04/24 08:19:30, 0, pid=696] /SourceCache/samba/samba-235.7/samba/source/nmdb_packets.c:precss_lanman_packet (1170)
process_lanman_packet: On subnet 192.168.15.100 ignoring browse packet command code 16898 from BlakesLaptop<01> IP 192.168.15.102 to WORKGROUP<00>

log.smdb

[2012/04/24 08:19:51, 0, pid=1136]/SourceCache/samba/samba-235.7/samba/source/passdb/pdb_odsam.c:odssam_ getsampwnam(1576)
opendirectory_sam_searchname gave -14136 [eDSRecordNotFound]: no dsRecTypeStandard:Users record for account 'Blake'

The one in log.smdb is repeated several times, probably during the time I was trying to access the share folder from my laptop running W7.

Another piece of possible important information is that the laptop is connected through ethernet to a dd-wrt routre running as a client bridge. My guess is thath there may be some setting on this client bridge router that got messed up.

Anyone have any ideas of how to get this to work or other log files/settings I should be checking?