Short answer. Yes, it is a problem. A verification based on "information and belief", or on "knowledge, information and belief", or that otherwise lacks a proper verification, is treated by the rules as if the pleading were unsigned — even though a signature and a verification page are physically attached to it.
What the law says
A pleading required to be verified that contains a verification based on "information and belief," or upon "knowledge, information and belief," or lacks a proper verification, shall be treated as an unsigned pleading.
Rule 7, Section 4 — Verification. Read the full provision →
What a proper verification has to say
A pleading is verified through an affidavit signed by someone duly authorized to do so, and where that person is signing on behalf of a party rather than personally, the authorization — a secretary's certificate or a special power of attorney — has to be attached. The verification itself must attest to three specific things: that the allegations are true and correct based on personal knowledge, or based on authentic documents; that the pleading is not filed to harass, delay, or needlessly run up the cost of litigation; and that the factual allegations have evidentiary support, or will have it after a reasonable opportunity for discovery.
Why 'information and belief' falls short
The rule is specific about the standard: allegations must be true and correct based on personal knowledge, or on authentic documents — not on what the affiant merely believes or has been told. A verification phrased as being based on "information and belief," or on "knowledge, information and belief," does not meet that standard, because it does not commit the affiant to personal knowledge of the facts. The rule treats this kind of hedge, and any verification that is otherwise improper or missing, the same way: as if the pleading carries no valid signature at all.
The consequence of being treated as unsigned
An unsigned pleading generally produces no legal effect and can be stricken or disregarded, which is a serious consequence for a case-initiating document like a complaint. The defect goes to the reliability of what is being sworn to, not to a mere technicality of form — the whole point of requiring personal knowledge is to make sure someone is actually vouching for the truth of the factual allegations, rather than simply repeating what they were told or assume to be true.
What to do if this applies to you
If your complaint's verification was worded as "information and belief" rather than personal knowledge, the safer course is to correct it by executing a proper verification that attests to personal knowledge or reliance on authentic documents, along with the other required attestations about the pleading not being filed for harassment or delay and having evidentiary support. Keep in mind this rule applies only to pleadings that are required to be verified in the first place — many ordinary pleadings need no verification at all, and this defect only matters where verification is legally required.