E6500 slow to connect to my router

I have a fairly old Linksys wireless router. My desktop computer connects reliably at 11MBPs, my old Dell Inspiron connects reliably, my new E6500 doesn't connect reliably. I have to try to connect several times to make it connect, and after it connects it is fairly slow. I was installing the latest Adobe Acrobat reader and it downloaded the 33MB file at a max. speed of 40kb/sec. I tried downloading some email attachments from hotmail.com and only got to about 8kb/s, the same file downloads to my desktop at 110kb/s.

I've been reading about problems with downloading through Vista, maybe a problem with scaling. Is my problem a Vista problem or a router problem because I have an old Linksys router?

 

It might be a problem with the antenna wiring. My E6400 was delivered from factory with one of the antenna cables not connected properly to the wireless card. Also there is a long antenna cable going to the monitor that is very tightly put under the bottom lid that might have been damaged.
Open the bottom lid and have a look.

Örjan