Linksys router problems

At work we've got a network with 8 machines. 4 are XP Pro and 4 are W2K.

The ISP provided modem/router doesn't have DHCP capability so all machines were connected by IP's assigned by the ISP.

For security reasons I wanted the router to assign the IP's. After 3 months of trying our ISP couldn't provide the type of router we wanted and told me to daisy chain one to their router.

So the setup I've got now is:

ISP provided modem/router >
Linksys BEFSR41 router >
2 hubs with 6 ports each >
8 machines.

The problems:

1) None of us can send an email with an attachment.

2) The owner does EBay, his machine and some others can't open EBay. I'm also unable to post to this forum from my work machine.

3) We've tried 2 Linksys routers, the first was occasionally dropping connection to 3 or 4 machines thoughout the day. This made the W2K machine we use as a print server to be unavailable. Rebooting the router fixed this, but a few hours later it would do the same thing. The second Linksys router still exhibits the first 2 problems, it hasn't been in the network long enough to know if it's going to drop connections to some machines.

With the first Linksys I was able to fix problem 2 by adjusting the MTU size setting from disabled to enabled and set to 1492. The second router isn't responding to MTU adjustments.

Any thoughts on this?

TIA