When I checked going to www.psi.net, I had several hops inside of Sprintlink with 10-30% packet loss. So, yes, I would say it causes problems.
$ date Tue Apr 4 14:34:42 PDT 2000 $ traceroute nisc.psi.net traceroute to nisc.psi.net (38.8.136.2), 30 hops max, 40 byte packets 1 216.32.113.130 (216.32.113.130) 1 ms 1 ms 1 ms 2 scca-21-f2-1-0.core.exodus.net (209.185.84.81) 1 ms 1 ms 1 ms 3 bbr01-g3-0.sntc03.exodus.net (216.33.153.65) 1 ms 1 ms 1 ms 4 bbr01-p6-0.sntc02.exodus.net (216.32.132.42) 1 ms 1 ms * 5 bbr02-p3-0.elsg01.exodus.net (209.185.249.218) 10 ms 10 ms 10 ms 6 ibr01-g5-0.elsg01.exodus.net (216.34.192.37) 10 ms 10 ms 10 ms 7 sl-gw15-ana-7-0.sprintlink.net (144.232.192.37) 12 ms 12 ms 12 ms 8 sl-bb12-ana-4-0.sprintlink.net (144.232.1.161) 12 ms 12 ms 12 ms 9 sl-bb10-ana-10-0.sprintlink.net (144.232.1.129) 12 ms 12 ms 12 ms 10 sl-bb12-fw-7-0.sprintlink.net (144.232.9.250) 36 ms 36 ms 36 ms 11 sl-bb11-pen-7-2.sprintlink.net (144.232.9.237) 78 ms 78 ms 78 ms 12 sl-bb13-pen-9-0.sprintlink.net (144.232.5.234) 78 ms 78 ms 78 ms 13 204.6.140.182 (204.6.140.182) 82 ms 83 ms 93 ms 14 38.1.10.23 (38.1.10.23) 92 ms 93 ms 97 ms 15 ftp.psi.net (38.8.136.2) 99 ms * 100 ms $ /usr/sbin/ping -s 38.8.136.2 PING 38.8.136.2: 56 data bytes 64 bytes from ftp.psi.net (38.8.136.2): icmp_seq=0. time=102. ms 64 bytes from ftp.psi.net (38.8.136.2): icmp_seq=1. time=105. ms 64 bytes from ftp.psi.net (38.8.136.2): icmp_seq=2. time=103. ms 64 bytes from ftp.psi.net (38.8.136.2): icmp_seq=3. time=96. ms 64 bytes from ftp.psi.net (38.8.136.2): icmp_seq=4. time=101. ms 64 bytes from ftp.psi.net (38.8.136.2): icmp_seq=5. time=105. ms 64 bytes from ftp.psi.net (38.8.136.2): icmp_seq=6. time=102. ms 64 bytes from ftp.psi.net (38.8.136.2): icmp_seq=7. time=106. ms 64 bytes from ftp.psi.net (38.8.136.2): icmp_seq=8. time=96. ms 64 bytes from ftp.psi.net (38.8.136.2): icmp_seq=9. time=106. ms 64 bytes from ftp.psi.net (38.8.136.2): icmp_seq=10. time=101. ms 64 bytes from ftp.psi.net (38.8.136.2): icmp_seq=11. time=108. ms 64 bytes from ftp.psi.net (38.8.136.2): icmp_seq=12. time=95. ms 64 bytes from ftp.psi.net (38.8.136.2): icmp_seq=13. time=100. ms 64 bytes from ftp.psi.net (38.8.136.2): icmp_seq=14. time=106. ms 64 bytes from ftp.psi.net (38.8.136.2): icmp_seq=15. time=99. ms 64 bytes from ftp.psi.net (38.8.136.2): icmp_seq=16. time=97. ms 64 bytes from ftp.psi.net (38.8.136.2): icmp_seq=17. time=103. ms 64 bytes from ftp.psi.net (38.8.136.2): icmp_seq=18. time=106. ms 64 bytes from ftp.psi.net (38.8.136.2): icmp_seq=19. time=101. ms 64 bytes from ftp.psi.net (38.8.136.2): icmp_seq=20. time=104. ms 64 bytes from ftp.psi.net (38.8.136.2): icmp_seq=21. time=107. ms 64 bytes from ftp.psi.net (38.8.136.2): icmp_seq=22. time=103. ms 64 bytes from ftp.psi.net (38.8.136.2): icmp_seq=23. time=96. ms 64 bytes from ftp.psi.net (38.8.136.2): icmp_seq=24. time=103. ms 64 bytes from ftp.psi.net (38.8.136.2): icmp_seq=25. time=95. ms ^C ----38.8.136.2 PING Statistics---- 26 packets transmitted, 26 packets received, 0% packet loss round-trip (ms) min/avg/max = 95/101/108