Thanks Thud.
Here is the dump with the -d option:
 1     3 ms     2 ms     1 ms  192.168.1.1
 2    10 ms    20 ms     8 ms  73.115.162.1
 3    38 ms     9 ms     9 ms  68.85.166.197
 4    13 ms    10 ms    12 ms  68.87.174.125
 5     *       10 ms    14 ms  68.87.174.178
 6    37 ms    21 ms    21 ms  68.86.95.193
 7    20 ms    20 ms    20 ms  68.86.87.130
 8    23 ms    22 ms    28 ms  192.205.37.117
 9    47 ms    46 ms    66 ms  12.122.86.42
10    53 ms    47 ms     *     12.122.2.22
11     *        *       45 ms  12.122.28.89
12   223 ms    60 ms    53 ms  12.122.28.85
13    80 ms    42 ms    43 ms  12.122.139.153
14    44 ms    44 ms    43 ms  12.122.254.154
15    92 ms    44 ms    49 ms  63.241.193.22
16    48 ms    55 ms    45 ms  206.16.60.39
and one more a few minutes later:
 1     3 ms     3 ms     9 ms  192.168.1.1
 2     *        *        *     Request timed out.
 3     *        *       20 ms  68.85.166.197
 4    11 ms    22 ms    14 ms  68.87.174.125
 5    13 ms    13 ms    12 ms  68.87.174.178
 6    27 ms    21 ms    18 ms  68.86.95.193
 7    30 ms    34 ms    26 ms  68.86.87.130
 8    24 ms    24 ms    22 ms  192.205.37.117
 9    72 ms    96 ms    48 ms  12.122.86.42
10     *        *       46 ms  12.122.2.22
11    46 ms    44 ms    46 ms  12.122.28.89
12    51 ms    56 ms    49 ms  12.122.28.85
13     *       43 ms    51 ms  12.122.139.153
14    50 ms    44 ms    47 ms  12.122.254.154
15    45 ms    46 ms    44 ms  63.241.193.22
16    52 ms    47 ms    52 ms  206.16.60.39
Could it be that the * (data loss??) up there are not due to comcast at all, but internal to my wireless network? I don't really have a clue here about this topic, so just guessing. It's not like the *s always show up against the same IP addresses.
I think the problem might be the combination of this linksys USB stick (811g) and my wireless router (811g+n, apple airport extreme). I tried doing tracert from a mac on the same wireless network, and it was perfectly clean (to the same IP as above). I found a couple PCI cards on newegg that are listed as 811n, I think one was $30 and the other was $50. The wife and kids watch a lot of streaming video on the internal network during the day, so I don't dare downgrade the airport to g-only mode. 
Hmm. maybe I could get a second cable modem, there is a cable socket in this room. Not sure how comcast would feel about that. If that was ok, then I could have a wired connection to this pc.