This is not a problem with JoomlaComment. Whoever made your template "myblogv2", they are bad at designing templates.
You can fix it by editing brick.css for the template. Go to line 14, where it should have...
.write_comment a.readon:link, .write_comment a.readon:visited {
...and in that style definition block, there is:
which is too small. Make it 360px - that's a good number for this situation. Alternatively, decrease the fontsize for that style definition.
EDIT: This is directed at Daniel if you read this (don't worry about this bit Gerard) - is there anything we can we do about this in future Daniel? I'm really tired of all these badly designed Joomla templates conflicting with JoomlaComment. Ah maybe I can just write a FAQ article or something, we don't really want to over-ride readon styling I suppose.