FYO: Odd Problem with Eudora sending attachments over (Centrino) wireless LAN

Hi.

During the last few days I have been trying to solve an odd problem
whereby I can't send attachments of size more than a few K from Eudora
6.0.X over a wireless LAN (through an ADSL firewall/router). This
appeared also to be related to a similar problem when trying to send
large emails, though the error messages were 10054 in the case of
attachments and 10053 in the case of emails!!

Initially I suspected my ISP was to blame. However, I was able to send
the same attachments using Outlook Express without any problem.

Last night I connected directly over Ethernet to the router (Netgear
DG824M) and the problem (with Eudora) disappeared.

So, not my ISP then, nor my router. I guessed it must be the built-in
Intel PRO/Wireless LAN Mini PCI Adapter.

Today I installed a Belkin Wireless PCMCIA card and, guess what, no
problems sending the attachments at all.

So. There appears to be a problem with Eudora and the Intel
PRO/Wireless adapter, I guess only to do with outgoing SMTP
connections.

Anyone have any thoughts on this? I would rather not have to use a
separate card (especially since it's the one from my girlfriend's
laptop).

Thanks.

Steve.