Integer parsing on indexes fails

Hey there, I'm getting a lot (%100 of my requests result in one) of these:
```
Error storing in Riak:  0: {precommit_fail,
    [{field_parsing_failed,{<<"images_int">>,<<6,0,0,0,0,0,0,0,0,0>>}},
     {field_parsing_failed,{<<"lastreply_int">>,<<0,0,0,0,0,0,0,0,0,0>>}},
     {field_parsing_failed,{<<"no_int">>,<<185,187,160,43,0,0,0,0,0,0>>}},
     {field_parsing_failed,{<<"replies_int">>,<<12,0,0,0,0,0,0,0,0,0>>}},
     {field_parsing_failed,
         {<<"tim_int">>,<<131,230,248,153,132,40,0,0,0,0>>}}]}
```

And here's my struct:
```
type Thread struct {
    Posts []Post `json:"posts"`
    No uint64 `riak:"index"`
    Replies     int `riak:"index"`
    Images     int `riak:"index"`
    Tim uint64 `riak:"index"`
    LastReply uint64 `riak:"index"`
}
```

Aaaand the code I'm using to insert it:
```
thread.No = thread.Posts[0].No
    thread.Replies = int(thread.Posts[0].Replies)
    thread.Images = int(thread.Posts[0].Images)
    thread.Tim = thread.Posts[0].Tim
    thread.LastReply = thread.Posts[len(thread.Posts)-1].Tim

    riakKey := fmt.Sprintf("t-%s-%d", board, thread.No)
    fmt.Println("Storing ", riakKey)

    _, err = RiakDBClient.StoreStruct("derpderp", riakKey, &thread)
    if err != nil {
        fmt.Println("Error storing in Riak: ", err)
    }
```