So, does no one have any advice for me on this?

Which was the exact text that was falsely reported as being more than 4 lines?

Anything I try over 2 lines does it. But here's an example one below (If i take out the third line of Join us today!, it works fine:
You'll never shine if you don't glow
http://www.vistababble.com
Join us today!

Works just fine for me:
http://www.vistababble.com/forums/members/kirby.html

So I see. I've attached a screenshot of the error message I get with that same signature.

That is WYSIWYG. Switch to Standard and make sure you really do not have more than 4 lines.
(Especially IE seems to add <br /> every now and then)

Yep, that was it! I imagine a lot of users might face the same problem, but at least now I'll know how to answer the question. Thanks.

does this work with img tags already used? say if i limit the imgs allowed to 3, users has 6 in there..will it alter his sig

I have installed this hack, but it isn't working correctly.

My limits are set to 400w x 100h, 30kb, 1 image only.

If I try and link to a signature that is too wide or too tall, the script rejects the signature. If I try and link to more than one image, the script rejects the signature.

However it is not imposing the filesize restrictions properly. At the moment I am linking to a 130kb BMP file as my signature and the script accepts this.

However, if I link to the same large image twice, it will say that the combined size of the images is too large.

I am running the plugin on vb3.5.3 and my forum is at forum.generationnetwork.co.uk
Any ideas why it's not working?

Is there an option to apply it it to certain usergroups?