Do you have the free Flickr account?

If you do you are limited to 300mg per month.

Flickr has a file size limit for a pro account of 20MB per image; it is less for a free Flickr account at 15MB    

http://www.flickr.com/help/photos/

It is also a shame that the LR Flickr publishing service does not check the size of the rendered file before it tries to send it to Flickr.   It just sends it regardless and consequently if the file is too large this wastes significant time and bandwidth whilst you wait for the error to occur.    It is also unfortunate that the error message is not explicit about which file actually failed.

I have already raised a couple of recommendations to Adobe on these issues …if you feel relevant then add your vote ...

http://feedback.photoshop.com/photoshop_family/topics/improve_flickr_p ublish_robustness_by_pre_checking_the_file_size_before_sending_to_flic kr

http://feedback.photoshop.com/photoshop_family/topics/improve_the_diag nostics_relating_to_flickr_publish_failures

The only suggestion I have is …

If you publishing jpegs, have you set your quality to 100%?   If so, unless using Flickr for archiving purposes, you could try reducing it to say 90% or so as this will make little discernible difference to the online viewing quality …

http://regex.info/blog/lightroom-goodies/jpeg-quality

and will reduce the file size to help mitigate the problem.

Alan.

Yes, I suspect that is what you are seeing.

I shoot with a 5D MK II most of the time and I find that perhaps 1 in 50 of my images exceed the 20MB limit if I have the quality set to 100% on the publish service.
At 91%  I get no failures and the quality is good enough - especially when Flickr itself has further quality issues, but thats another story.

The other alternative is instead of setting 90% quality you could set the maximum file size limit to 20000 KB.   
This sounds the usful way of doing things as you would think it would only ever reduce the quality of images when they are larger than this.  
Unfortunately this is not the case it will cause quality reduction on all files regardless of size.

Alan

Assuming I’ve understood what you’ve said … it sounds like you have manually put some of your images to Flickr outside of using LR to do it.    If true,  despite the problems you are currently seeing, which I hope are reduced or eliminated if you lower the publish quality setting,  I really recommend letting LR fully manage the publishing of all your shots to Flickr (or Smugmug etc) and avoid using any direct upload methods outside of LR.

There are many reasons for this recommendation … if you change the development, keywording, title, caption etc of any published shot using LR then it will remind you the image needs republishing.    If you publish the same photo using both LR and manually copying it up using other means then Flickr will probably end up considering these as two different photos and longer term leading to chaos.     If other Flickr users comment on your photos then Lightroom will copy these comments back to the Lightroom database for you.

Again, I recommend setting the publishing quality to 90% and let LR completely manage your publishing needs.

However … to answer your direct question of how to remove them from the publishing queue (i.e. any photo being shown by LR as needing publishing or republishing) … you should be able to right click the thumbnail in the grid in library view and use the “Mark as Up-To-Date” menu.     (Note this is only possible in LR4 not LR3).

Hope this helps.