axelget, yum and crccheck failed

axelget, yum and crccheck failed

I want to increase my download speed with yum and finally found a solution (axelget) that works fine at the beginning. But after one time work, I get an error and I cannot use it any more because of "crc" problem!
[root@dhcppc0 ali]# yum update -y
Loaded plugins: axelget, fastestmirror, langpacks, presto, refresh-packagekit
No metadata available for fedora
No metadata available for google-chrome
No metadata available for rpmfusion-free
No metadata available for rpmfusion-free-updates
No metadata available for rpmfusion-nonfree
No metadata available for rpmfusion-nonfree-updates
No metadata available for updates
Finish Download MetaData of Enabled Repo
Loading mirror speeds from cached hostfile
 * fedora: www.ftp.ne.jp
 * rpmfusion-free: mirror.nexcess.net
 * rpmfusion-free-updates: mirror.nexcess.net
 * rpmfusion-nonfree: mirror.nexcess.net
 * rpmfusion-nonfree-updates: mirror.nexcess.net
 * updates: www.ftp.ne.jp
Resolving Dependencies
...
Upgrade  11 Packages
Total download size: 6.8 M
Downloading Packages:

CRC check failed 0x84dd7640 != 0xbf02314L
Here is another log :
[root@dhcppc0 ali]# yum install axel
Loaded plugins: axelget, fastestmirror, langpacks, presto, refresh-packagekit
fedora/18/x86_64/metalink                                                             | 9.7 kB  00:00:00    
google-chrome                                                                         |  951 B  00:00:00    
rpmfusion-free                                                                        | 3.3 kB  00:00:00    
rpmfusion-free-updates                                                                | 3.3 kB  00:00:00    
rpmfusion-nonfree                                                                     | 3.3 kB  00:00:00    
rpmfusion-nonfree-updates                                                             | 3.3 kB  00:00:00    
updates/18/x86_64/metalink                                                            | 5.7 kB  00:00:00    
(1/2): rpmfusion-nonfree-updates/primary_db                                           | 133 kB  00:00:04    
(2/2): rpmfusion-free-updates/primary_db                                              | 329 kB  00:00:12    
repomd.xml                                                                            | 4.2 kB  00:00:00    
Initializing download: tp://ftp.riken.jp/Linux/fedora/releases/18/Everything/x86_64/os/repodata/7606e9d3ed634ddab6e4f2317fe2b647f7f20f00cc183613338d3929e2c4ccc0-prestodelta.xml.gz
File size: 1574148 bytes
Opening output file /var/cache/yum/x86_64/18/fedora/7606e9d3ed634ddab6e4f2317fe2b647f7f20f00cc183613338d3929e2c4ccc0-prestodelta.xml.gz
Starting download

Connection 0 finished                                                          ]
Connection 3 finished                                                          ]
Connection 1 finished                                                          ]
Connection 2 finished                                                          ]
[100%] [..................................................] [  43.5KB/s] [00:00]

Downloaded 1537.3 kilobytes in 35 seconds. (43.54 KB/s)
update fedora metadata sucessfully
repomd.xml