What does the task log say ?
Hi, did you try to check in "all" at once (for that product) or each one seperately?
Usally I check in extension (only) first, then product help, then installers etc.
Checking in all at once often couses issues.
If it still doesn't work - ckick on "download" link instead of "check in" - does the download work? If not then it's maybe a firewall/proxy issue?