You're not the only one with that problem. From day to day more people have it.
Look at this:
http://www.cisco.com/en/US/tech/tk827/t ... 3f1f.shtml
You're not _browsing_ but it's quite the same thing. It's important if the other servers filter ICMP packets. For the internet it's important that ICMP works and they just don't think and filter it. There needs to be an ICMP-filter in place and there needs to be some link which has a MTU below 1500 bytes. This is true, for example, on most ATM links - and on many VLANs. It's also true for tunnels of any kind. The eggdrop developers could do a complete workaround if they just don't set the "DF"-bit on each outgoing packet. It's the combination of the ICMP-filter on one side and some MTU below 1500 on the internet or on the other side.
The only final solution could be done on the other side(s). They just need to allow fragmentation-needed-ICMP-requests _or_ they need to clear the DF bit within their router on each outgoing packet.
If anyone of these routers is using an ATM-link with a MTU below 1500 bytes or using VLANs or something else which isn't able to transfer 1500 bytes in one packet, you can't solve the problem on you side. It may work with a userfile below some 1200 bytes but this doesn't really help you. (reference: sewi@Euro-IRC)
It's maybe to late for you, but from day to day more ppl have that problem, vhere bots share channel file but not userfiles.