Cap'n Waffoo,
Capital letter after a semi-colon? (line 1)
This type of Internet forum tends to generate a lot of "train of thought" type postings and as such grammar and syntax tend to fall by the wayside. I see no problem with this at all. Additionally, the odd typo and punctuation failure are forgivable as we are not all dictation typists. That said, people will form a subconscious opinion of a poster if all his/her postings are littered with basic "you're/your" and "their/there" type blunders.
As IFR said though, as long as one gets one's point across clearly and concisely then what's the harm? On that note then, may I request that people actually read through their postings before pressing the Send button; some of the things that appear on these pages are utterly incomprehensible.
