I stopped playing for now because I got 90k 3 times in the last hour always in dungeon.
However there is 2 of us playing - first 2 times only affected me and the last time affected both of us.

The time it affected both of us we both noticed the game lagged up couldn't move or interact with anything but the fc chat was still running. That says to me It is the instance servers causing this problem.

My connection is fine checked every time after I got a 90k. Did a tracert result.
Microsoft Windows [Version 6.1.7601]
Copyright (c) 2009 Microsoft Corporation. All rights reserved.

C:\Users\shaun>tracert 199.91.189.74

Tracing route to 199.91.189.74 over a maximum of 30 hops

1 <1 ms <1 ms <1 ms 192.168.1.1
2 8 ms 6 ms 7 ms 10.240.84.1
3 6 ms 8 ms 7 ms bmly-core-2b-xe-1132-0.network.virginmedia.net [
213.105.193.121]
4 9 ms 7 ms 9 ms brnt-bb-1a-ae13-0.network.virginmedia.net [213.1
05.159.229]
5 7 ms 7 ms 6 ms brnt-bb-2a-ae2-0.network.virginmedia.net [62.254
.42.97]
6 12 ms 13 ms 13 ms brhm-bb-2a-ae0-0.network.virginmedia.net [62.254
.42.58]
7 31 ms 12 ms 11 ms brhm-bb-1b-ae0-0.network.virginmedia.net [62.254
.42.106]
8 16 ms 17 ms 15 ms teln-ic-1-ae0-0.network.virginmedia.net [212.43.
163.250]
9 15 ms 14 ms 13 ms m282-mp2.cvx3-a.ltn.dial.ntli.net [213.104.85.26
]
10 14 ms 14 ms 15 ms be2398.ccr21.lon01.atlas.cogentco.com [130.117.5
1.209]
11 15 ms 15 ms 14 ms be2316.mpd21.lon13.atlas.cogentco.com [154.54.73
.113]
12 21 ms 21 ms 22 ms be2285.ccr21.lpl01.atlas.cogentco.com [130.117.4
9.126]
13 92 ms 94 ms 92 ms be2384.ccr21.ymq02.atlas.cogentco.com [154.54.44
.137]
14 101 ms 90 ms 93 ms 38.122.42.34
15 * * * Request timed out.
16 92 ms 90 ms 91 ms 192.34.76.2
17 91 ms 91 ms 92 ms 199.91.189.234
18 91 ms 91 ms 91 ms 199.91.189.74

Trace complete.

C:\Users\shaun>

Never have any problems normally on server whenever I get a lag spike/90k boot I am in some form of instance.