I have a HTC desire with Froyo, stock rom (Orange 184.108.40.206). I never had any problems with Gmail (version 2.3.2). However, since a couple of days when I try to send attachments (any kind, pdf, pictures, etc.) it just hangs.
The mails are in the outbox but don't get sent and Gmail doesn't synchronize anymore. If I delete the mails from the outbox, Gmail still fails to synchronize. To resurrect it I have to force stop it and clear its cache.
There is constant internet connection through WIFI and I can browse, access the net through other apps with no problems. Current space on the phone, 15.7MB internal and 55MB on the sd card.